Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.69% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-94422High confidence
xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape
Fedora · Fedora
8.7HighCVSS 4.0
Patch only the product branches with a verified fix
Fix availability varies by productHigh technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 34 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 severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Fedora Fedora 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 34 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Red Hat Product Security: 2 affected or under-investigation product states without a fixed product state in the same current advisory
- SUSE Product Security Team: 31 affected or under-investigation product states without a fixed product state in the same current advisory
- Debian Security Tracker: 1 affected package state 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 1 affected package state 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 | xdg-dbus-proxy | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.1.6-1+deb13u3 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | xdg-dbus-proxy | 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 | xdg-dbus-proxy | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.1.9-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | xdg-dbus-proxy | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.1.9-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | xdg-dbus-proxy | 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
2 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-2026-94422 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityxdg-dbus-proxy: xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape
The vendor explicitly identifies these products as affected by this CVE.
- xdg-dbus-proxy.src as a component of Red Hat Enterprise Linux 10
- xdg-dbus-proxy.src as a component of Red Hat Enterprise Linux 9
- Summary
- An incorrect implementation of message filtering in xdg-dbus-proxy versions before 0.1.9 allows an attacker to bypass the intended message filtering on the D-Bus session bus by setting a reply serial number on non-reply messages. A malicious or compromised Flatpak app could use this to achieve arbitrary code execution outside its sandbox.
- Remediation
- Avoid running untrusted Flatpak apps and avoid running untrusted apps via other frameworks that use xdg-dbus-proxy.
CVE-2026-94422 · CSAF 2.0 · revision 2 · interimSUSE Product Security TeamCVE-2026-94422
The vendor explicitly identifies these products as affected by this CVE.
- xdg-dbus-proxy as component of SUSE Linux Enterprise Desktop 15 SP7
- xdg-dbus-proxy as component of SUSE Linux Enterprise High Performance Computing 15 SP2
- xdg-dbus-proxy as component of SUSE Linux Enterprise High Performance Computing 15 SP3
- xdg-dbus-proxy as component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS
- xdg-dbus-proxy as component of SUSE Linux Enterprise High Performance Computing 15 SP4
- xdg-dbus-proxy as component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
- xdg-dbus-proxy as component of SUSE Linux Enterprise High Performance Computing 15 SP5
- xdg-dbus-proxy as component of SUSE Linux Enterprise Module for Basesystem 15 SP7
- xdg-dbus-proxy as component of SUSE Linux Enterprise Server 15 SP2-LTSS
- xdg-dbus-proxy as component of SUSE Linux Enterprise Server 15 SP2
- xdg-dbus-proxy as component of SUSE Linux Enterprise Server 15 SP3-LTSS
- xdg-dbus-proxy as component of SUSE Linux Enterprise Server 15 SP3
- Summary
- unknown
- Remediation
- No remediation text is recorded.
High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 34 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
An incorrect implementation of message filtering in xdg-dbus-proxy versions before 0.1.9 allows an attacker to bypass the intended message filtering on the D-Bus session bus by setting a reply serial number on non-reply messages. A malicious or compromised Flatpak app could use this to achieve arbitrary code execution outside its sandbox. xdg-dbus-proxy was designed to be part of the sandbox boundary for Flatpak, but it is released as a separate project and is sometimes used by other app frameworks such as Firejail.
What
An incorrect implementation of message filtering in xdg-dbus-proxy versions before 0.1.9 allows an attacker to bypass the intended message filtering on the D-Bus session bus by setting a reply serial number on non-reply messages. A malicious or compromised Flatpak app could use this to achieve arbitrary code execution outside its sandbox. xdg-dbus-proxy was designed to be part of the sandbox boundary for Flatpak, but it is released as a separate project and is sometimes used by other app frameworks such as Firejail.
Why
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
How
An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
What
An incorrect implementation of message filtering in xdg-dbus-proxy versions before 0.1.9 allows an attacker to bypass the intended message filtering on the D-Bus session bus by setting a reply serial number on non-reply messages. A malicious or compromised Flatpak app could use this to achieve arbitrary code execution outside its sandbox. xdg-dbus-proxy was designed to be part of the sandbox boundary for Flatpak, but it is released as a separate project and is sometimes used by other app frameworks such as Firejail.
Why
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
How
An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
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
- a network path → Authentication Bypass by Spoofing → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Passive interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-290 ↗
CWE-290: Authentication Bypass by Spoofing. This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIPassiveUser interaction: A user must unknowingly interact with the vulnerable system.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
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
- 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
- Avoid running untrusted Flatpak apps and avoid running untrusted apps via other frameworks that use xdg-dbus-proxy.
Official vendor articles1 stored document
Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.
- CVE-2026-94422 | Ubuntu →Original publisher ↗Searchable text snapshot · Captured 26 Sep 2026CVE-2026-94422 Publication date 23 September 2026 Last updated 24 September 2026 Ubuntu priority Medium Why this priority? Toggle side navigation Description security update Status Show unmaintained releases Package Ubuntu Release Status xdg-dbus-proxy 26.04 LTS resolute Needs evaluation 24.04 LTS noble Ne
04
Evidence and provenance
Published 2 Oct 2026 · Last source change 2 Oct 2026, 16:51 UTC · CWE-290 · Authentication Bypass by Spoofing
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-10-03
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-91646
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
- ENISA EUVD mappingEUVD-2026-91646 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-91646"}
- Vendor guidanceAuthoritative vendor guidance changed: removed patch: github.com/e4465a0dfe96da3b39929a30a1ac3a22b16223e3; removed patch: github.com/e5702fca4dba9600721921fbca2dbc39dc5ca400; 3 further removals.CNA ↗
- Before
- patch: github.com/e4465a0dfe96da3b39929a30a1ac3a22b16223e3 · patch: github.com/e5702fca4dba9600721921fbca2dbc39dc5ca400 · patch: github.com/fc027f759316fb2a6c45648200b6f100202eb84e · 2 more references
- After
- no authoritative guidance recorded
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- < 0.1.9; Fedora: < 0.1.9 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- After
- < 0.1.9; Fedora: < 0.1.9 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- Remediation statusRemediation status changed from Patch available to Awaiting fix.CNA ↗
- Before
- Patch available
- After
- Awaiting fix
- Vendor guidanceAuthoritative vendor guidance changed: added patch: github.com/e4465a0dfe96da3b39929a30a1ac3a22b16223e3; added patch: github.com/e5702fca4dba9600721921fbca2dbc39dc5ca400; removed remediation: ubuntu.com/CVE-2026-94422; removed vendor advisory: ubuntu.com/CVE-2026-94422; 3 further additions.github.com ↗
- Before
- remediation: ubuntu.com/CVE-2026-94422 · vendor advisory: ubuntu.com/CVE-2026-94422
- After
- patch: github.com/e4465a0dfe96da3b39929a30a1ac3a22b16223e3 · patch: github.com/e5702fca4dba9600721921fbca2dbc39dc5ca400 · patch: github.com/fc027f759316fb2a6c45648200b6f100202eb84e · 2 more references
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- Ubuntu 24.04 LTS · standard · xdg-dbus-proxy: might be affected and may need fixing · Fixed: Canonical has not published a fixed package version in this OVAL definition.
- After
- < 0.1.9; Fedora: < 0.1.9 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Remediation statusRemediation status changed from Under evaluation to Patch available.github.com ↗
- Before
- Under evaluation
- After
- Patch available
- SeveritySeverity changed from Unknown to High.CNA ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 8.7 (CVSS 4.0 · CNA · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N).CNA ↗
- Before
- not recorded
- After
- 8.7 (CVSS 4.0 · CNA · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)
- Catalogue recordCVE added to the BlackTree catalogue.Authoritative vendor OVAL definition ↗
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.