Vulnerability record · CVE-2026-67291 · published 1 August 2026
CVE-2026-67291: Freerdp out-of-bounds read vulnerability
Freerdp · Freerdp
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.
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:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f | Patch |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hgj8-g595-wfc6 | ExploitVendor Advisory |
| https://www.vulncheck.com/advisories/freerdp-before-heap-out-of-bounds-read-via-glyph-fragment-add | PatchThird Party Advisory |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hgj8-g595-wfc6 | ExploitVendor Advisory |
Track CVE-2026-67291 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-67291), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.
