CVE-2026-43894
jq: Wild stack write via signed-integer overflow in decNumber D2U() macro
- State
- Published
- Severity
- 6.2 Medium
- Published
- May 11, 2026
- Updated
- May 11, 2026
- Reserved
- May 4, 2026
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).
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.2 Medium | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
Weaknesses
- CWE-190 Integer Overflow or Wraparound
Affected Products
| Product | Versions |
|---|---|
jqjqlang |
|
References
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