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CVE PROGRAM SOURCE RECORD6.2 Medium

CVE-2026-43894

jq: Wild stack write via signed-integer overflow in decNumber D2U() macro

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).

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

jqlang jq

  • <= 1.8.1affected

References