FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains a heap out-of-bounds read in… (CVE-2026-67291)
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.
AI Analysis
Technical Summary
The vulnerability in FreeRDP before version 3.29.0 (affecting versions up to 3.28.0) is a heap out-of-bounds read in the functions update_process_glyph_fragments() and glyph_cache_fragment_put() within libfreerdp/cache/glyph.c. The issue arises because the code reads a one-byte server-controlled declared fragment size without verifying that this size fits within the remaining received buffer. This lack of bounds checking allows a malicious RDP server to send a short fragment with an oversized declared size, leading to an out-of-bounds read and a client crash.
Potential Impact
An attacker controlling an RDP server can cause a FreeRDP client to crash by sending a specially crafted GLYPH_FRAGMENT_ADD update with an invalid fragment size. This results in a denial of service (client crash). There is no indication of confidentiality or integrity impact from the provided data.
Mitigation Recommendations
No patch or official fix information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid connecting FreeRDP clients to untrusted or potentially malicious RDP servers to mitigate risk.
FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains a heap out-of-bounds read in… (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 v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in FreeRDP before version 3.29.0 (affecting versions up to 3.28.0) is a heap out-of-bounds read in the functions update_process_glyph_fragments() and glyph_cache_fragment_put() within libfreerdp/cache/glyph.c. The issue arises because the code reads a one-byte server-controlled declared fragment size without verifying that this size fits within the remaining received buffer. This lack of bounds checking allows a malicious RDP server to send a short fragment with an oversized declared size, leading to an out-of-bounds read and a client crash.
Potential Impact
An attacker controlling an RDP server can cause a FreeRDP client to crash by sending a specially crafted GLYPH_FRAGMENT_ADD update with an invalid fragment size. This results in a denial of service (client crash). There is no indication of confidentiality or integrity impact from the provided data.
Mitigation Recommendations
No patch or official fix information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid connecting FreeRDP clients to untrusted or potentially malicious RDP servers to mitigate risk.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-qx25-fqx8-cgm7
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-67291"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a6e6298bf32cb7a344f9d37
Added to database: 08/01/2026, 21:18:16 UTC
Last enriched: 08/01/2026, 21:24:45 UTC
Last updated: 09/15/2026, 22:01:36 UTC
Views: 47
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