Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.12% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-88265High confidence
Crun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown
Red Hat · Red Hat Hardened Images
Official source article: Red Hat RHSA-2026:71668 ↗. Check the applicable product and release in the original source.
5.6MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Low, lowered one band.downgradedsince 2 Oct 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Red Hat Red Hat Hardened Images and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Debian Security Tracker: 4 affected package states with no published fix
Distribution package intelligence
5 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
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 4 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 release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | crun | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | crun | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | crun | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | crun | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | crun | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
Direct vendor intelligence
1 currentAuthoritative 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.
CVE-2026-88265 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitycrun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown
The vendor explicitly identifies these products as affected by this CVE.
- crun as a component of Red Hat Enterprise Linux 10
- crun-krun as a component of Red Hat Enterprise Linux 10
- crun.src as a component of Red Hat Enterprise Linux 10
- crun.src (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8
- crun (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8
- crun as a component of Red Hat Enterprise Linux 9
- crun.src as a component of Red Hat Enterprise Linux 9
- crun as a component of Red Hat OpenShift Container Platform 4
- crun.src as a component of Red Hat OpenShift Container Platform 4
- openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4
- openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4
- Summary
- A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.
- Remediation
- For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.
What
A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.
Why
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.
Why
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 Link Resolution Before File Access ('Link Following') → cause the confidentiality, integrity or availability impact described by the vendor
- 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-59 ↗
CWE-59: Improper Link Resolution Before File Access ('Link Following'). The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
- 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:N/I:H/A:NCommon 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.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
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
- crun as a component of Red Hat Enterprise Linux 10
- crun-krun as a component of Red Hat Enterprise Linux 10
- crun.src as a component of Red Hat Enterprise Linux 10
- crun.src (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8
- crun (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8
- crun as a component of Red Hat Enterprise Linux 9
- crun.src as a component of Red Hat Enterprise Linux 9
- crun as a component of Red Hat OpenShift Container Platform 4
- crun.src as a component of Red Hat OpenShift Container Platform 4
- openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4
- openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4
- Fixed
- crun-0:1.30-1.hum1@aarch64 as a component of Red Hat Hardened Images
- crun-0:1.30-1.hum1@src as a component of Red Hat Hardened Images
- crun-0:1.30-1.hum1@x86_64 as a component of Red Hat Hardened Images
- crun-krun-0:1.30-1.hum1@aarch64 as a component of Red Hat Hardened Images
- crun-krun-0:1.30-1.hum1@x86_64 as a component of Red Hat Hardened Images
- crun-wasm-0:1.30-1.hum1@aarch64 as a component of Red Hat Hardened Images
- crun-wasm-0:1.30-1.hum1@x86_64 as a component of Red Hat Hardened Images
- 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
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 10 Sept 2026 · Last source change 2 Oct 2026, 13:59 UTC · CWE-59 · Improper Link Resolution Before File Access ('Link Following')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-10
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-75360
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
View recent updates ↗What changed after publication
- Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: access.redhat.com/RHSA-2026:71668.CNA ↗
- Before
- remediation: access.redhat.com/RHSA-2026:71668 · vendor advisory: access.redhat.com/RHSA-2026:71668
- After
- remediation: access.redhat.com/RHSA-2026:71668
- Vendor guidanceAuthoritative vendor guidance changed: added remediation: access.redhat.com/RHSA-2026:71668; added vendor advisory: access.redhat.com/RHSA-2026:71668.access.redhat.com ↗
- Before
- no authoritative guidance recorded
- After
- remediation: access.redhat.com/RHSA-2026:71668 · vendor advisory: access.redhat.com/RHSA-2026:71668
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- See the vendor and CVE records for the affected range. · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- See the vendor and CVE records for the affected range. · Fixed: Red Hat Hardened Images: 1.30-1.hum1 < *
- Remediation statusRemediation status changed from Awaiting fix to Patch available.access.redhat.com ↗
- Before
- Awaiting fix
- After
- Patch available
- Vendor guidanceAuthoritative vendor guidance changed from remediation: access.redhat.com/CVE-2026-88265 to remediation: access.redhat.com/CVE-2026-88265.Red Hat Product Security ↗
- Before
- remediation: access.redhat.com/CVE-2026-88265
- After
- remediation: access.redhat.com/CVE-2026-88265
- Remediation statusRemediation status changed from Mitigation available to Patch available.Red Hat Product Security ↗
- Before
- Mitigation available
- After
- Patch available
- Affected versionsThe structured affected or fixed version information changed.Red Hat Product Security ↗
- Before
- crun.src as a component of Red Hat Hardened Images
- After
- crun as a component of Red Hat Enterprise Linux 10; crun-krun as a component of Red Hat Enterprise Linux 10; crun.src as a component of Red Hat Enterprise Linux 10; crun.src (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; crun (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8; crun as a component of Red Hat Enterprise Linux 9; crun.src as a component of Red Hat Enterprise Linux 9; crun as a component of Red Hat OpenShift Container Platform 4; crun.src as a component of Red Hat OpenShift Container Platform 4; openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · Fixed: crun-0:1.30-1.hum1@aarch64 as a component of Red Hat Hardened Images; crun-0:1.30-1.hum1@src as a component of Red Hat Hardened Images; crun-0:1.30-1.hum1@x86_64 as a component of Red Hat Hardened Images; crun-krun-0:1.30-1.hum1@aarch64 as a component of Red Hat Hardened Images; crun-krun-0:1.30-1.hum1@x86_64 as a component of Red Hat Hardened Images; crun-wasm-0:1.30-1.hum1@aarch64 as a component of Red Hat Hardened Images; crun-wasm-0:1.30-1.hum1@x86_64 as a component of Red Hat Hardened Images
- ENISA EUVD mappingEUVD-2026-75360 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-75360"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
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.