CVE-2025-26599: xserver · Access of Uninitialized Pointer
Affects xserverSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 5 Nov 2026, 00:01 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 7.8 |
|---|
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Feb 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| xserver | Affected
| Fixed in– |
AI-suggested
An official patch is available as per the Red Hat security advisory RHSA-2025:2500. Users of affected Red Hat Enterprise Linux 9 variants should apply the update promptly to remediate this vulnerability. No additional mitigation steps are required beyond applying the vendor-provided fix.
Description
CVE-2025-26599 is a high-severity vulnerability in the X.Org xserver and Xwayland components involving an access of an uninitialized pointer. The flaw occurs when the function compCheckRedirect() fails to allocate a backing pixmap, causing compRedirectWindow() to return a BadAlloc error without properly validating the window tree. This results in partially initialized data and subsequent use of an uninitialized pointer, which can lead to serious impacts on confidentiality, integrity, and availability.
References
- access.redhat.com/errata/RHSA-2025:2500 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2502 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2861 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2862 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2865 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2866 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2873 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2874 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2875 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2879 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:2880 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:3976 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:7163 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:7165 (opens in a new tab)
- access.redhat.com/errata/RHSA-2025:7458 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2025-26599 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2345253 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/02/msg00036.html (opens in a new tab)