Process crash via unbounded jv_contains recursion
Published May 11, 2026 · Updated May 11, 2026
Uncontrolled recursion in jv_contains in jq 1.8.1 and earlier allows local users to crash the jq process via deeply nested arrays or objects. The array and object containment helpers call jv_contains recursively without a depth limit, so contains() or inside() exhausts the C stack. Exploitation requires a jq program that constructs a sufficiently deep structure, and the demonstrated result on Linux is a process-ending segmentation fault.
Summary
What happened
Uncontrolled recursion in jv_contains in jq 1.8.1 and earlier allows local users to crash the jq process via deeply nested arrays or objects. The array and object containment helpers call jv_contains recursively without a depth limit, so contains() or inside() exhausts the C stack. Exploitation requires a jq program that constructs a sufficiently deep structure, and the demonstrated result on Linux is a process-ending segmentation fault.
The record
- CVE
- CVE-2026-40612
- Published
- May 11, 2026
- Updated
- May 11, 2026
- Vendor
- jqlang
- Product
- jq
- Classifications
- CWE-674, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 11, 2026CVE publishedPublication date reported by the CVE source.
- May 11, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=<= 1.8.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- jv_contains stack-exhaustion proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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