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20Track

Red Hat Enterprise Linux: Buffer overflow

Red Hat Enterprise Linux · CVE-2026-50256 ZDI-26-903
0 news outlets0 CERTs and agencies1 research labs

Assessment: Track

SSVC decision points: exploitation none, automatable no, technical impact total, deployment low.

What is it?

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but libXfont2's alias target name length is 1024 bytes. A font alias name between 257 and 1023 bytes causes the X server to copy that name into the undersized stack buffer without further checks. This may be used to crash the server, or for privilege escalation if the X server runs as root.

Evidence

Technical advisories1Detailed write-ups from security research teams

Exploitation

  • Exploit code published (not verified by us)
  • Exploited in the wild (confirmed by a source)
  • Listed as known exploited (CISA KEV)
CVSS
7.8
EPSS
0.2%
First seen
22 h ago
Status
confirmed

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