CVE-2026-43894 Details
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).
A heap-based buffer overflow vulnerability has been identified in jq, a command-line JSON processor, in versions through 1.8.1. The issue arises in the decNumber library when the decNumberFromString function is fed a number literal of INT_MAX-1 digits. This input causes a signed integer overflow in the D2U macro, which is then exploited to bypass heap-allocation size checks. As a result, the function incorrectly uses a 30-byte stack buffer, writing approximately 715 million 16-bit units (around 1.4 GiB) at an offset of 1.43 GiB below the stack frame. The overflowed data is fully controlled by the attacker, allowing for potential exploitation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 11, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-190 | Integer Overflow or Wraparound | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| jqlang jq | <= 1.8.1 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 13, 2026 | Initial Analysis | [email protected] |
| May 11, 2026 | CVE Modified | CISA-ADP |
| May 11, 2026 | New CVE Received | [email protected] |