Process crash via unchecked directory pathname formatting
Published Jul 13, 2026 · Updated Jul 13, 2026
Stack-based buffer overflow in GNU Awk 5.4.0 and earlier allows local users to crash gawk while reading a crafted directory. The readdir extension's ftype() routine uses sprintf() to join an attacker-influenced directory path and entry name into a PATH_MAX stack buffer without checking the combined length. The extension must be loaded and process the crafted directory; code execution is unconfirmed, so the established consequence is a process crash.
Summary
What happened
Stack-based buffer overflow in GNU Awk 5.4.0 and earlier allows local users to crash gawk while reading a crafted directory. The readdir extension's ftype() routine uses sprintf() to join an attacker-influenced directory path and entry name into a PATH_MAX stack buffer without checking the combined length. The extension must be loaded and process the crafted directory; code execution is unconfirmed, so the established consequence is a process crash.
The record
- CVE
- CVE-2026-40553
- Published
- Jul 13, 2026
- Updated
- Jul 13, 2026
- Vendor
- The GnuPG Project
- Product
- GNU Awk
- Classifications
- CWE-121
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 13, 2026CVE publishedPublication date reported by the CVE source.
- Jul 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <=5.4.0
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What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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