What’s Vulnerable › Vulnerabilities
CVE-2026-6791: Potential stack-based buffer clash during tilde expansion in wordexp
- Severity: medium (CVSS 6.6 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-10 · updated 2026-10-24
- Weakness: CWE-121
Description
When expanding paths that begin with a tilde (~) followed by a username, the internal parse_tilde function extracts the username to determine the user's home directory. The implementation allocates memory for this username directly on the stack using the strndupa macro. Because the size of this allocation was determined by the length of the user-supplied input without any bounds checks, passing an excessively long username e.g. thousands of characters, forces the thread to exhaust its stack space. Thus if an application passes untrusted, attacker-controlled input to the wordexp function, an attacker can trigger a stack clash.
Affected products
- GNU C Library (glibc): from 2.0 through 2.43
References
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