CVE-2026-50256: Red Hat Enterprise Linux 10 · Stack-based Buffer Overflow
Affects Red Hat Enterprise Linux 10Source CVE Database V5
Not known to be exploited · CVSS 7.8 High.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% 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 5 Jun 2026
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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10xorg-x11-server-Xwayland | Affected– | Fixed in– |
| Red Hat Enterprise Linux 10.0 Extended Update Supportxorg-x11-server-Xwayland | Affected– | Fixed in– |
| Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSIONtigervnc | Affected– | Fixed in– |
| Red Hat Enterprise Linux 7 Extended Lifecycle Supportxorg-x11-server | Affected– | Fixed in– |
| Red Hat Enterprise Linux 7 Extended Lifecycle Supporttigervnc | Affected– | Fixed in– |
| Red Hat Enterprise Linux 8xorg-x11-server-Xwayland | Affected– | Fixed in– |
AI-suggested
Red Hat has released official security updates addressing this vulnerability in the xorg-x11-server and xorg-x11-server-Xwayland packages for Red Hat Enterprise Linux 8. Users should apply the updates as described in Red Hat Advisory RHSA-2026:26562. Patch status is confirmed by the vendor advisory. No additional mitigation is required beyond applying the official fixes.
Description
A stack-based buffer overflow vulnerability exists in the X.Org X server and Xwayland due to a mismatch in maximum font name length handling between the X server and the libXfont2 library. The X server allocates a 256-byte stack buffer, but libXfont2 allows font alias names up to 1024 bytes. When a font alias name between 257 and 1023 bytes is processed, it can overflow the stack buffer, potentially causing a server crash or privilege escalation if the server runs as root. This vulnerability affects Red Hat Enterprise Linux 8 and has been addressed by Red Hat in security updates.
References
- access.redhat.com/errata/RHSA-2026:26562 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26566 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26590 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26610 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26709 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:28923 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29844 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36083 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36085 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36086 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36087 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36632 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36633 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36634 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36768 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36791 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36792 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36798 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38502 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38810 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46377 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46382 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46385 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46392 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46456 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46460 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46473 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49519 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-50256 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2485380 (opens in a new tab)
- gitlab.freedesktop.org/xorg/xserver/-/commit/bb5158f962dc935e58ef8b4b5fcb31be201a6e07 (opens in a new tab)
- lists.x.org/archives/xorg-announce/2026-June/003702.html (opens in a new tab)
- redhat.atlassian.net/browse/PSIRTSUPT-16950 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50256.json (opens in a new tab)