CVE-2026-105842: Heap-based Buffer Overflow in Uwe Ohse lrzsz
Description
lrzsz before 0.13.0 contains a heap-based buffer overflow vulnerability in procheader() of the lrz receive utility when copying overlong sender-supplied filenames into Pathname. Malicious ZMODEM senders can supply filenames up to 8192 bytes, overflowing the buffer via sprintf() in pipe mode or strcpy() to corrupt heap memory and crash lrz.
CVSS v4.0
Score 6.1medium
Affected software
Uwe Ohse
lrzsz
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability exists in lrzsz versions prior to 0.13.0 in the procheader() function of the lrz receive utility. When a ZMODEM sender supplies an excessively long filename (up to 8192 bytes), the code copies this filename into a fixed-size buffer using unsafe functions like sprintf() or strcpy() in pipe mode. This causes a heap-based buffer overflow, corrupting heap memory and potentially crashing the application.
Potential Impact
An attacker controlling the ZMODEM sender can trigger a heap-based buffer overflow by sending an overlong filename, causing memory corruption and crashing the lrzsz receive utility. This could lead to denial of service or potentially other undefined behavior due to heap corruption. No information about code execution or privilege escalation is provided.
Mitigation Recommendations
A fix is available in lrzsz version 0.13.0. Users should upgrade to version 0.13.0 or later to remediate this vulnerability. No other mitigation guidance is provided.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-05T22:00:10.842Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac4fc542cdf04f656b4d690
Added to database: 10/06/2026, 13:49:08 UTC
Last enriched: 10/06/2026, 14:05:23 UTC
Last updated: 10/06/2026, 20:04:26 UTC
Views: 12
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