# CVE-2025-26597: Xorg: xwayland: buffer overflow in xkbchangetypesofkey()

Status: published. Published: 2025-02-25. Updated: 2026-11-04.

A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called with a non-zero value of groups, this will cause a buffer overflow because the key actions are of the wrong size.

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. (source: CNA: redhat)

## Affected products and versions

-  /  (xserver): ≥ 0; < 21.1.16 (affected, semver); ≥ 22.0.0; < 24.1.6 (affected, semver). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (xorg-x11-server-Xwayland): ≥ 0:24.1.5-3.el10_0; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 Extended Lifecycle Support  - EXTENSION (tigervnc): ≥ 0:1.1.0-25.el6_10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 Extended Lifecycle Support (tigervnc): ≥ 0:1.8.0-36.el7_9; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 Extended Lifecycle Support (xorg-x11-server): ≥ 0:1.20.4-30.el7_9; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (tigervnc): ≥ 0:1.13.1-15.el8_10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.2 Advanced Update Support (tigervnc): ≥ 0:1.9.0-15.el8_2.13; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support (tigervnc): ≥ 0:1.11.0-8.el8_4.12; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.4 Telecommunications Update Service (tigervnc): ≥ 0:1.11.0-8.el8_4.12; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions (tigervnc): ≥ 0:1.11.0-8.el8_4.12; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support (tigervnc): ≥ 0:1.12.0-6.el8_6.13; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.6 Telecommunications Update Service (tigervnc): ≥ 0:1.12.0-6.el8_6.13; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions (tigervnc): ≥ 0:1.12.0-6.el8_6.13; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.8 Extended Update Support (tigervnc): ≥ 0:1.12.0-15.el8_8.12; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (tigervnc): ≥ 0:1.14.1-1.el9_5.1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (xorg-x11-server): ≥ 0:1.20.11-28.el9_6; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (xorg-x11-server-Xwayland): ≥ 0:23.2.7-3.el9_6; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions (tigervnc): ≥ 0:1.11.0-22.el9_0.13; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.2 Extended Update Support (tigervnc): ≥ 0:1.12.0-14.el9_2.10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.4 Extended Update Support (tigervnc): ≥ 0:1.13.1-8.el9_4.5; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (xorg-x11-server): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (xorg-x11-server): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (xorg-x11-server-Xwayland): Version range not reported. Source: CNA: redhat

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:tigervnc:tigervnc:-:*:*:*:*:*:*:*",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  },
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "21.1.16",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "24.1.6",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  },
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H; source: CNA: redhat

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H; source: NVD: nvd@nist.gov

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.44% as of 2026-11-04; percentile 38.73%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-119

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2025:2500 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2502 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2861 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2862 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2865 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2866 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2873 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2874 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2875 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2879 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:2880 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:3976 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:7163 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:7165 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:7458 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2025-26597 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2345255 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html (ADP: CVE)

- http://www.openwall.com/lists/oss-security/2026/06/02/1 (ADP: CVE)

- https://access.redhat.com/errata/RHSA-2025:2500 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2502 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2861 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2862 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2865 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2866 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2873 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2874 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2875 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2879 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:2880 (secalert@redhat.com; Third Party Advisory)

- https://access.redhat.com/errata/RHSA-2025:3976 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2025:7163 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2025:7165 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2025:7458 (secalert@redhat.com)

- https://access.redhat.com/security/cve/CVE-2025-26597 (secalert@redhat.com; Third Party Advisory)

- https://bugzilla.redhat.com/show_bug.cgi?id=2345255 (secalert@redhat.com; Issue Tracking)

- http://www.openwall.com/lists/oss-security/2026/06/02/1 (af854a3a-2127-422b-91ae-364da2661108)

- https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html (af854a3a-2127-422b-91ae-364da2661108)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2025-26597; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-26597; retrieved 2026-11-05; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2025-26597; retrieved 2026-11-04; source updated Not reported

Revision: 9f1cc66d964399635b2a08bcc40255ae8a55fe0bde7d5c5961e2d2ac0c08fa1c

Canonical: https://y2.dev/cve/CVE-2025-26597

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