CVE-2026-41257: Jqlang Jq

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

jq is a command-line JSON processor. In 1.8.1 and earlier, the jq bytecode VM's data stack tracks its allocation size in a signed int. When the stack grows beyond ≈1 GiB (via deeply nested generator forks), the doubling arithmetic overflows. The wrapped value is passed to realloc and then used for a memmove with attacker-influenced offsets.

Affected products

• Jqlang Jq: up to and including 1.8.1

Published 2026-05-11. Last modified 2026-06-17.