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Full vulnerability report · 2026
CVE-2026-18107High confidence

Criu: criu: container escape via rseq critical section hijack during checkpoint/restore

Red Hat · Red Hat Enterprise Linux 10

7.8HighCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 35 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Medium, lowered one band.downgradedsince 1 Sep 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.11% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Red Hat Red Hat Enterprise Linux 10 and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 35 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

4 package states
Package result overrides the generic status

BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 2 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.

Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcecriuAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcecriuAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcecriuVendor fix publishedDebian records a fixed source-package version for this release.4.2-5Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcecriuVendor fix publishedDebian records a fixed source-package version for this release.4.2-5Debian Security Tracker ↗Source updated 6 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-18107 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitycriu: criu: container escape via rseq critical section hijack during checkpoint/restore
33 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • crit as a component of Red Hat Enterprise Linux 10
  • criu-devel as a component of Red Hat Enterprise Linux 10
  • criu-libs as a component of Red Hat Enterprise Linux 10
  • criu.src as a component of Red Hat Enterprise Linux 10
  • python3-criu as a component of Red Hat Enterprise Linux 10
  • crit as a component of Red Hat Enterprise Linux 7
  • criu.src as a component of Red Hat Enterprise Linux 7
  • python-criu as a component of Red Hat Enterprise Linux 7
  • crit as a component of Red Hat Enterprise Linux 8
  • crit (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8
  • criu as a component of Red Hat Enterprise Linux 8
  • criu-devel as a component of Red Hat Enterprise Linux 8
Summary
A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore. A malicious process inside a container can register an rseq critical section that hijacks CRIU's parasite code injection during checkpoint, allowing it to spoof the process credentials saved in the checkpoint image. On restore, the container process gains elevated capabilities and zeroed UIDs/GIDs. The practical impact on Red Hat products is limited by several factors: checkpoint/restore requires root privileges (podman) or cluster-admin RBAC (OpenShift) to trigger and cannot be initiated from within the container itself; on OpenShift prior to 4.17 the feature required explicit opt-in, and on 4.17+ the kubelet checkpoint API RBAC is not configured by default; OpenShift enforces user namespaces by default for regular workloads (hostUsers is gated behind admin-only SCCs), which makes the spoofed capabilities namespace-scoped and ineffective for privilege escalation; SELinux type enforcement (container_t) blocks privilege transitions independently of capabilities; seccomp filters persist through checkpoint/restore and cannot be corrupted via the parasite; and kernel mount namespace ownership checks on RHEL 9/10 kernels prevent mount-based container escape even with spoofed capabilities.
Remediation
Disable checkpoint/restore functionality in the container runtime if it is not required. If checkpoint/restore is needed, ensure containers run with user namespaces enabled, which limits the scope of spoofed capabilities to the user namespace.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-49986

No EUVD known-exploited evidence

A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore. A malicious process inside a container can register an rseq critical section that hijacks CRIU's parasite code injection during checkpoint, allowing it to spoof the process credentials saved in the checkpoint image. On restore, the container process gains elevated capabilities and zeroed UIDs/GIDs. The practical impact on Red Hat products is limited by several factors: checkpoint/restore requires root privileges (podman) or cluster-admin RBAC (OpenShift) to trigger and cannot be initiated from within the container itself; on OpenShift prior to 4.17 the feature required explicit opt-in, and on 4.17+ the kubelet checkpoint API RBAC is not configured by default; OpenShift enforces user namespaces by default for regular workloads (hostUsers is gated behind admin-only SCCs), which makes the spoofed capabilities namespace-scoped and ineffective for privilege escalation; SELinux type enforcement (container_t) blocks privilege transitions independently of capabilities; seccomp filters persist through checkpoint/restore and cannot be corrupted via the parasite; and kernel mount namespace ownership checks on RHEL 9/10 kernels prevent mount-based container escape even with spoofed capabilities.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 35 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore. A malicious process inside a container can register an rseq critical section that hijacks CRIU's parasite code injection during checkpoint, allowing it to spoof the process credentials saved in the checkpoint image. On restore, the container process gains elevated capabilities and zeroed UIDs/GIDs. The practical impact on Red Hat products is limited by several factors: checkpoint/restore requires root privileges (podman) or cluster-admin RBAC (OpenShift) to trigger and cannot be initiated from within the container itself; on OpenShift prior to 4.17 the feature required explicit opt-in, and on 4.17+ the kubelet checkpoint API RBAC is not configured by default; OpenShift enforces user namespaces by default for regular workloads (hostUsers is gated behind admin-only SCCs), which makes the spoofed capabilities namespace-scoped and ineffective for privilege escalation; SELinux type enforcement (container_t) blocks privilege transitions independently of capabilities; seccomp filters persist through checkpoint/restore and cannot be corrupted via the parasite; and kernel mount namespace ownership checks on RHEL 9/10 kernels prevent mount-based container escape even with spoofed capabilities.

What

A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore. A malicious process inside a container can register an rseq critical section that hijacks CRIU's parasite code injection during checkpoint, allowing it to spoof the process credentials saved in the checkpoint image. On restore, the container process gains elevated capabilities and zeroed UIDs/GIDs. The practical impact on Red Hat products is limited by several factors: checkpoint/restore requires root privileges (podman) or cluster-admin RBAC (OpenShift) to trigger and cannot be initiated from within the container itself; on OpenShift prior to 4.17 the feature required explicit opt-in, and on 4.17+ the kubelet checkpoint API RBAC is not configured by default; OpenShift enforces user namespaces by default for regular workloads (hostUsers is gated behind admin-only SCCs), which makes the spoofed capabilities namespace-scoped and ineffective for privilege escalation; SELinux type enforcement (container_t) blocks privilege transitions independently of capabilities; seccomp filters persist through checkpoint/restore and cannot be corrupted via the parasite; and kernel mount namespace ownership checks on RHEL 9/10 kernels prevent mount-based container escape even with spoofed capabilities.

Why

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore. A malicious process inside a container can register an rseq critical section that hijacks CRIU's parasite code injection during checkpoint, allowing it to spoof the process credentials saved in the checkpoint image. On restore, the container process gains elevated capabilities and zeroed UIDs/GIDs. The practical impact on Red Hat products is limited by several factors: checkpoint/restore requires root privileges (podman) or cluster-admin RBAC (OpenShift) to trigger and cannot be initiated from within the container itself; on OpenShift prior to 4.17 the feature required explicit opt-in, and on 4.17+ the kubelet checkpoint API RBAC is not configured by default; OpenShift enforces user namespaces by default for regular workloads (hostUsers is gated behind admin-only SCCs), which makes the spoofed capabilities namespace-scoped and ineffective for privilege escalation; SELinux type enforcement (container_t) blocks privilege transitions independently of capabilities; seccomp filters persist through checkpoint/restore and cannot be corrupted via the parasite; and kernel mount namespace ownership checks on RHEL 9/10 kernels prevent mount-based container escape even with spoofed capabilities.

Why

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Improper Privilege Management → gain additional privileges
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-269 ↗

CWE-269: Improper Privilege Management. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
Privilege escalationCWE-269
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-49986Official EUVD mapping

A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore. A malicious process inside a container can register an rseq critical section that hijacks CRIU's parasite code injection during checkpoint, allowing it to spoof the process credentials saved in the checkpoint image. On restore, the container process gains elevated capabilities and zeroed UIDs/GIDs. The practical impact on Red Hat products is limited by several factors: checkpoint/restore requires root privileges (podman) or cluster-admin RBAC (OpenShift) to trigger and cannot be initiated from within the container itself; on OpenShift prior to 4.17 the feature required explicit opt-in, and on 4.17+ the kubelet checkpoint API RBAC is not configured by default; OpenShift enforces user namespaces by default for regular workloads (hostUsers is gated behind admin-only SCCs), which makes the spoofed capabilities namespace-scoped and ineffective for privilege escalation; SELinux type enforcement (container_t) blocks privilege transitions independently of capabilities; seccomp filters persist through checkpoint/restore and cannot be corrupted via the parasite; and kernel mount namespace ownership checks on RHEL 9/10 kernels prevent mount-based container escape even with spoofed capabilities.

Official EUVD record ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260729Security Bulletin 29 Jul 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 29 Jul 2026, published on 29 July 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
Disable checkpoint/restore functionality in the container runtime if it is not required. If checkpoint/restore is needed, ensure containers run with user namespaces enabled, which limits the scope of spoofed capabilities to the user namespace.
04

Evidence and provenance

Published 28 Jul 2026 · Last source change 1 Sept 2026, 12:47 UTC · CWE-269 · Improper Privilege Management

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-49986
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    crit as a component of Red Hat Enterprise Linux 10; criu-devel as a component of Red Hat Enterprise Linux 10; criu-libs as a component of Red Hat Enterprise Linux 10; criu.src as a component of Red Hat Enterprise Linux 10; python3-criu as a component of Red Hat Enterprise Linux 10; crit as a component of Red Hat Enterprise Linux 7; criu.src as a component of Red Hat Enterprise Linux 7; python-criu as a component of Red Hat Enterprise Linux 7; crit as a component of Red Hat Enterprise Linux 8; crit (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu as a component of Red Hat Enterprise Linux 8; criu-devel as a component of Red Hat Enterprise Linux 8; criu-devel (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu-libs as a component of Red Hat Enterprise Linux 8; criu-libs (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu.src as a component of Red Hat Enterprise Linux 8; criu.src (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; python3-criu as a component of Red Hat Enterprise Linux 8; python3-criu (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; crit as a component of Red Hat Enterprise Linux 9; criu-devel as a component of Red Hat Enterprise Linux 9; criu-libs as a component of Red Hat Enterprise Linux 9; criu.src as a component of Red Hat Enterprise Linux 9; python3-criu as a component of Red Hat Enterprise Linux 9; crit as a component of Red Hat OpenShift Container Platform 4; criu as a component of Red Hat OpenShift Container Platform 4; criu-devel as a component of Red Hat OpenShift Container Platform 4; criu-libs as a component of Red Hat OpenShift Container Platform 4; criu.src as a component of Red Hat OpenShift Container Platform 4; and 2 more
    After
    crit as a component of Red Hat Enterprise Linux 10; criu-devel as a component of Red Hat Enterprise Linux 10; criu-libs as a component of Red Hat Enterprise Linux 10; criu.src as a component of Red Hat Enterprise Linux 10; python3-criu as a component of Red Hat Enterprise Linux 10; crit as a component of Red Hat Enterprise Linux 7; criu.src as a component of Red Hat Enterprise Linux 7; python-criu as a component of Red Hat Enterprise Linux 7; crit as a component of Red Hat Enterprise Linux 8; crit (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu as a component of Red Hat Enterprise Linux 8; criu-devel as a component of Red Hat Enterprise Linux 8; criu-devel (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu-libs as a component of Red Hat Enterprise Linux 8; criu-libs (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu.src as a component of Red Hat Enterprise Linux 8; criu.src (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; criu (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; python3-criu as a component of Red Hat Enterprise Linux 8; python3-criu (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; crit as a component of Red Hat Enterprise Linux 9; criu-devel as a component of Red Hat Enterprise Linux 9; criu-libs as a component of Red Hat Enterprise Linux 9; criu.src as a component of Red Hat Enterprise Linux 9; python3-criu as a component of Red Hat Enterprise Linux 9; crit as a component of Red Hat OpenShift Container Platform 4; criu as a component of Red Hat OpenShift Container Platform 4; criu-devel as a component of Red Hat OpenShift Container Platform 4; criu-libs as a component of Red Hat OpenShift Container Platform 4; criu.src as a component of Red Hat OpenShift Container Platform 4; and 3 more
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-49986↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-18107 · cve.blacktree.nl