Process crash via dangling AWK replacement pointer
Published Jul 15, 2026 · Updated Jul 15, 2026
Use-after-free in BusyBox awk 1.38.0 and earlier allows local users to crash the process by running a crafted AWK script. The awk_sub() function retains a replacement-text pointer into AWK variable storage, but as_regex() can change that storage before strlen() and the substitution loop dereference the pointer. The crafted script must reach a BusyBox awk invocation, and the demonstrated consequence is a process crash rather than a system-wide outage.
Summary
What happened
Use-after-free in BusyBox awk 1.38.0 and earlier allows local users to crash the process by running a crafted AWK script. The awk_sub() function retains a replacement-text pointer into AWK variable storage, but as_regex() can change that storage before strlen() and the substitution loop dereference the pointer. The crafted script must reach a BusyBox awk invocation, and the demonstrated consequence is a process crash rather than a system-wide outage.
The record
- CVE
- CVE-2026-38753
- Published
- Jul 15, 2026
- Updated
- Jul 15, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-416, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 15, 2026CVE publishedPublication date reported by the CVE source.
- Jul 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Attacks
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Technologies
Your stack
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Your stack
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