CVE-2026-67291

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.

CVSS Vector

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