What’s Vulnerable › Vulnerabilities

CVE-2026-67291: FreeRDP before 3.29.0 Heap Out-of-Bounds Read via GLYPH_FRAGMENT_ADD

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-08-01 · updated 2026-09-03
• Weakness: CWE-125

Description

FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains a heap out-of-bounds read in update_process_glyph_fragments()/glyph_cache_fragment_put() in libfreerdp/cache/glyph.c. When handling a GLYPH_FRAGMENT_ADD update, the code reads a one-byte server-controlled declared fragment size but does not verify it fits within the remaining received buffer before allocating and copying that many bytes. A malicious RDP server can send a short fragment with an oversized declared size, causing the client to read beyond the allocated buffer, resulting in an out-of-bounds read and client crash.

Affected products

• FreeRDP: before 3.29.0 — fixed in 3.29.0

How to fix

Upgrade to a fixed version: FreeRDP 3.29.0. Check the vendor advisory for mitigations.

References

• https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hgj8-g595-wfc6
• https://www.vulncheck.com/advisories/freerdp-before-heap-out-of-bounds-read-via-glyph-fragment-add
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hgj8-g595-wfc6

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