Vulnerability Description
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).
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Jqlang | Jq | <= 1.8.1 |
Related Weaknesses (CWE)
References
- https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4gExploitMitigationVendor Advisory
- https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4gExploitMitigationVendor Advisory
FAQ
What is CVE-2026-43894?
CVE-2026-43894 is a vulnerability with a CVSS score of 6.2 (MEDIUM). 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. ...
How severe is CVE-2026-43894?
CVE-2026-43894 has been rated MEDIUM with a CVSS base score of 6.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-43894?
Check the references section above for vendor advisories and patch information. Affected products include: Jqlang Jq.