Out-of-bounds write in jq - CVE-2026-43894

Vulnerability identifier: #VU130926

CSH Severity: Low

CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-43894

CWE-ID: CWE-787

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to out-of-bounds write in decNumber D2U() macro in decNumberFromString when processing an extremely large decimal string via tonumber. A remote attacker can supply a specially crafted number string to cause a denial of service.

The issue is triggered by signed integer overflow and is reachable through tonumber on a string built via the multiplication operator rather than through raw JSON number parsing.

jq
Debian Linux
openEuler
Anolis OS
LANTIME Operating System Firmware (LTOS)
jq (Debian package)
jq
jq-help
jq-devel
jq-debugsource
jq-debuginfo
jq-doc

Install update from vendor's website.

jq - update to 1.8.2
LANTIME Operating System Firmware (LTOS) - update to 7.10.013
jq (Debian package) - update to 1.7.1-6+deb13u3
jq - update to 1.8.0-4
jq-help - update to 1.8.0-4
jq-devel - update to 1.8.0-4
jq-debugsource - update to 1.8.0-4
jq-debuginfo - update to 1.8.0-4
jq - update to 1.8.1-8
jq-doc - update to 1.8.1-8
jq-devel - update to 1.8.1-8

• https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g

• Multiple vulnerabilities in jq
• Anolis OS update for jq
• Multiple vulnerabilities in Meinberg LANTIME firmware
• Debian update for jq
• openEuler 24.03 LTS SP3 update for jq
• openEuler 24.03 LTS update for jq
• openEuler 22.03 LTS SP4 update for jq
• openEuler 20.03 LTS SP4 update for jq
• openEuler 24.03 LTS SP1 update for jq