Review reviewHigh

CVE-2025-26595

Red Hat Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION, Red Hat Enterprise Linux 7 Extended Lifecycle Support

A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.

CVSS
7.8
EPSS
0.43%
35.3% percentile
CISA KEV
Not listed
Published
2025.02.26
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.43%
Technical severityCVSS 7.8

Vulnerability overview

A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.

Affected product and versions

Product
Red Hat Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION, Red Hat Enterprise Linux 7 Extended Lifecycle Support
Affected versions
22.0.0, < 21.1.16, < 24.1.6, 7.0, 8.0, 9.0
Fixed versions
21.1.16, 24.1.6

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Red Hat Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION, Red Hat Enterprise Linux 7 Extended Lifecycle Support and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-121, CWE-787