CVE-2026-67291
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
0.4%
29.0th percentile
CISA KEV
Not listed
Weakness / dates
CWE-125
Published 2026-08-01 · modified 2026-09-03
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | N | None |
| Availability | H | High |
Timeline
- 2026-08-01 — Published (NVD)
- 2026-09-03 — Last modified (NVD)
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
References
- https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f
- exploit 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
- exploit https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hgj8-g595-wfc6