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CVE Record

CVE-2025-26598: Xorg: xwayland: out-of-bounds write in createpointerbarrierclient()

An out-of-bounds write flaw was found in X.Org and Xwayland. The function GetBarrierDevice() searches for the pointer device based on its device ID and returns the matching value, or supposedly NULL, if no match was found. However, the code will return the last element of the list if no matching device ID is found, which can lead to out-of-bounds memory access.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This is a local memory-corruption flaw in X.Org/Xwayland-related server code. A logged-in local user could potentially crash or compromise a graphical server process. Business urgency is highest for Linux desktops, VDI, remote GUI, and systems where untrusted users can obtain shell or graphical-session access.

Executive priority

Treat as high priority where Linux graphical infrastructure is shared or remotely accessible. It is not documented as actively exploited in the supplied sources, but successful local exploitation could affect confidentiality, integrity, and availability of the graphical server context.

Technical view

GetBarrierDevice() may return the last list element instead of NULL when no pointer device ID matches. createpointerbarrierclient() can then reach out-of-bounds memory access. The source rates it CVSS 7.8, CWE-787, local attack vector, low complexity, low privileges, no user interaction, and high confidentiality, integrity, and availability impact.

Likely exposure

Affected exposure includes listed Red Hat Enterprise Linux 6 ELS, 7 ELS, 8, 9, 10, and related AUS/EUS/E4S/TUS/SAP streams running vulnerable xorg-x11-server, xorg-x11-server-Xwayland, or tigervnc packages. Debian LTS also published an advisory. Other distributions may need vendor confirmation.

Exploitation context

The provided bundle does not show CISA KEV listing or confirmed active exploitation. The CVSS vector indicates local exploitation by a low-privileged user without user interaction, so risk depends on local account access, shared workstations, remote GUI services, and multi-user Linux environments.

Researcher notes

Evidence supports a local out-of-bounds write in pointer barrier handling. The bundle gives affected Red Hat package streams and advisories, plus Debian LTS notice, but does not include exploit proof, patch diff details, or universal upstream/distribution coverage. Avoid assuming internet-remote exposure.

Mitigation direction

  • Apply relevant vendor security updates for affected Xorg, Xwayland, or TigerVNC packages.
  • Prioritize shared Linux hosts, VDI pools, jump boxes, and systems with untrusted local users.
  • Check Red Hat advisories for the exact product stream and package version.
  • Review Debian LTS guidance if managing Debian-based affected systems.
  • Restrict local shell and graphical-session access where patching is delayed.
  • Monitor vendor advisories for additional distributions or revised package status.

Validation and detection

  • Inventory installed xorg-x11-server, xorg-x11-server-Xwayland, and tigervnc package versions.
  • Map each host to the affected product streams listed in vendor advisories.
  • Confirm security errata installation through your package-management and vulnerability-scanning records.
  • Check for exposed VNC or remote GUI services on affected Linux hosts.
  • Validate that compensating access controls cover unpatched multi-user systems.
Prepared
Confidence
high
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-787: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2025-26598 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
5Timeline events
2ADP providers
19Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9redhat

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2025-26598Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. Source timelineredhat

    Reported to Red Hat.

  3. Source timelineredhat

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Unknown vendorxserverxserver, 0, 22.0.0unaffected
Red HatRed Hat Enterprise Linux 10xorg-x11-server-Xwayland, 0:24.1.5-3.el10_0affected
Red HatRed Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSIONtigervnc, 0:1.1.0-25.el6_10affected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Supporttigervnc, 0:1.8.0-36.el7_9affected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Supportxorg-x11-server, 0:1.20.4-30.el7_9affected
Red HatRed Hat Enterprise Linux 8tigervnc, 0:1.13.1-15.el8_10affected
Red HatRed Hat Enterprise Linux 8.2 Advanced Update Supporttigervnc, 0:1.9.0-15.el8_2.13affected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supporttigervnc, 0:1.11.0-8.el8_4.12affected
Red HatRed Hat Enterprise Linux 8.4 Telecommunications Update Servicetigervnc, 0:1.11.0-8.el8_4.12affected
Red HatRed Hat Enterprise Linux 8.4 Update Services for SAP Solutionstigervnc, 0:1.11.0-8.el8_4.12affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supporttigervnc, 0:1.12.0-6.el8_6.13affected
Red HatRed Hat Enterprise Linux 8.6 Telecommunications Update Servicetigervnc, 0:1.12.0-6.el8_6.13affected
Red HatRed Hat Enterprise Linux 8.6 Update Services for SAP Solutionstigervnc, 0:1.12.0-6.el8_6.13affected
Red HatRed Hat Enterprise Linux 8.8 Extended Update Supporttigervnc, 0:1.12.0-15.el8_8.12affected
Red HatRed Hat Enterprise Linux 9tigervnc, 0:1.14.1-1.el9_5.1affected
Red HatRed Hat Enterprise Linux 9xorg-x11-server, 0:1.20.11-28.el9_6affected
Red HatRed Hat Enterprise Linux 9xorg-x11-server-Xwayland, 0:23.2.7-3.el9_6affected
Red HatRed Hat Enterprise Linux 9.0 Update Services for SAP Solutionstigervnc, 0:1.11.0-22.el9_0.13affected
Red HatRed Hat Enterprise Linux 9.2 Extended Update Supporttigervnc, 0:1.12.0-14.el9_2.10affected
Red HatRed Hat Enterprise Linux 9.4 Extended Update Supporttigervnc, 0:1.13.1-8.el9_4.5affected
Red HatRed Hat Enterprise Linux 6xorg-x11-serverunknown
Red HatRed Hat Enterprise Linux 8xorg-x11-serverunaffected
Red HatRed Hat Enterprise Linux 8xorg-x11-server-Xwaylandunaffected
Weakness

CWE details

CWE-787

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-787 · source CWE mapping

Out-of-bounds Write

Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs