CVE-2026-111145: Out-of-bounds Read in Yeraze ytnef
Description
CVE-2026-111145 is a heap out-of-bounds read vulnerability in ytnef versions up to 2.1.2. The flaw exists in the DecompressRTF() function, which fails to validate the uncompressedSize of RTF streams. This can be triggered by a crafted winmail.dat TNEF attachment containing a malicious PT_BINARY MAPI property, potentially causing a crash and leaking adjacent heap memory.
CVSS v4.0
Score 6.9medium
Affected software
Yeraze
ytnef
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
ytnef through version 2.1.2 contains a heap out-of-bounds read vulnerability in the DecompressRTF() function located in lib/ytnef.c. The vulnerability arises because the function does not validate the uncompressedSize parameter for uncompressed RTF streams. An attacker can exploit this by supplying a specially crafted winmail.dat TNEF attachment with a malicious PT_BINARY MAPI property, which may cause ytnefprint or other libytnef callers to crash and leak adjacent heap memory.
Potential Impact
Successful exploitation can lead to a denial of service via application crash and potential information disclosure through leaking adjacent heap memory. The vulnerability requires local access (AV:L) and user interaction (UI:P), with no privileges required (PR:N). The impact is limited to local attackers who can supply crafted input to the vulnerable function.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, avoid processing untrusted winmail.dat TNEF attachments with ytnef or related tools to mitigate risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-15T17:03:58.228Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad123b62cdf04f65652b700
Added to database: 10/15/2026, 19:04:22 UTC
Last enriched: 10/15/2026, 19:48:33 UTC
Last updated: 10/15/2026, 19:48:33 UTC
Views: 3
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