CVE-2025-26596: Out-of-bounds Write
A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.
AI Analysis
Technical Summary
This vulnerability involves a heap overflow in the XkbWriteKeySyms() function within X.Org and Xwayland components. The root cause is a mismatch in length calculation compared to XkbSizeKeySyms(), which can result in writing beyond allocated buffer boundaries. This flaw can lead to memory corruption, potentially allowing an attacker with local privileges to execute arbitrary code or cause denial of service. The issue is tracked as CVE-2025-26596 with a CVSS score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). Red Hat has issued patches for affected versions of Red Hat Enterprise Linux 8 and 9, including various architectures such as x86_64, s390x, ppc64le, and aarch64. The vendor advisory is the authoritative source for remediation details.
Potential Impact
Successful exploitation of this heap overflow can lead to complete compromise of confidentiality, integrity, and availability of affected systems. The vulnerability requires local access with low privileges and no user interaction. It may allow an attacker to execute arbitrary code or cause a denial of service via memory corruption. There are no reports of active exploitation in the wild currently.
Mitigation Recommendations
Red Hat has released official patches for this vulnerability in their tigervnc and xorg-x11-server packages for Red Hat Enterprise Linux 8 and 9. Users should apply these updates promptly according to the instructions in the Red Hat advisories RHSA-2025:2500 and RHSA-2025:2502. The vendor manages remediation through these updates; no additional mitigations are indicated in the advisory. Patch status is confirmed as official-fix.
CVE-2025-26596: Out-of-bounds Write
Description
A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a heap overflow in the XkbWriteKeySyms() function within X.Org and Xwayland components. The root cause is a mismatch in length calculation compared to XkbSizeKeySyms(), which can result in writing beyond allocated buffer boundaries. This flaw can lead to memory corruption, potentially allowing an attacker with local privileges to execute arbitrary code or cause denial of service. The issue is tracked as CVE-2025-26596 with a CVSS score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). Red Hat has issued patches for affected versions of Red Hat Enterprise Linux 8 and 9, including various architectures such as x86_64, s390x, ppc64le, and aarch64. The vendor advisory is the authoritative source for remediation details.
Potential Impact
Successful exploitation of this heap overflow can lead to complete compromise of confidentiality, integrity, and availability of affected systems. The vulnerability requires local access with low privileges and no user interaction. It may allow an attacker to execute arbitrary code or cause a denial of service via memory corruption. There are no reports of active exploitation in the wild currently.
Mitigation Recommendations
Red Hat has released official patches for this vulnerability in their tigervnc and xorg-x11-server packages for Red Hat Enterprise Linux 8 and 9. Users should apply these updates promptly according to the instructions in the Red Hat advisories RHSA-2025:2500 and RHSA-2025:2502. The vendor manages remediation through these updates; no additional mitigations are indicated in the advisory. Patch status is confirmed as official-fix.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- redhat
- Date Reserved
- 2025-02-12T14:12:22.795Z
- Cisa Enriched
- true
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 682cd0fc1484d88663aecbf6
Added to database: 5/20/2025, 6:59:08 PM
Last enriched: 4/7/2026, 5:52:21 AM
Last updated: 5/10/2026, 5:50:19 AM
Views: 66
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