jq is a command-line JSON processor. In 1.8.1 and earlier, when decNumberFromString is given a number literal of INT_MAX-1 (2147483646) digits, the D2U() macro overflows during signed-int arithmetic. The wrapped negative value bypasses the heap-allocation size check, causes the function to use a 30-byte stack buffer, and then writes ≈715 million 16-bit units (≈1.4 GiB) at an offset 1.43 GiB below the stack frame. The written content is fully attacker-controlled (the parsed decimal digits, packed 3-per-unit).
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g Exploit, Mitigation, Vendor Advisory
- https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g Exploit, Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.5 · jqlangNVD modified 2026-10-26 18:10
Affected (CPE criteria) 1
cpe:2.3:a:jqlang:jq:*:*:*:*:*:*:*:*
References 2
- https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g Exploit, Mitigation, Vendor Advisory
- https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g Exploit, Mitigation, Vendor Advisory