CVE-2026-41256

Description

jq is a command-line JSON processor. In 1.8.1 and earlier, Top-level jq programs loaded from a file with -f are truncated at the first embedded NUL byte on current upstream HEAD. A crafted filter file such as . followed by \x00 and arbitrary suffix compiles and executes as only the prefix before the NUL. This leaves jq with a post-CVE-2026-33948 prefix/full-buffer mismatch on the compilation path even though the JSON parser path has already been fixed.

CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-158 CWE-158

Affected Products

Vendor	Product	Versions
jqlang	jq	< 1.8.1

References

Advisories & Patches

https://github.com/jqlang/jq/security/advisories/GHSA-vf2h-chrj-q3fg https://github.com/jqlang/jq/security/advisories/GHSA-vf2h-chrj-q3fg

Exploits

https://github.com/jqlang/jq/security/advisories/GHSA-vf2h-chrj-q3fg https://github.com/jqlang/jq/security/advisories/GHSA-vf2h-chrj-q3fg

Frequently Asked Questions

What is CVE-2026-41256? +

jq is a command-line JSON processor. In 1.8.1 and earlier, Top-level jq programs loaded from a file with -f are truncated at the first embedded NUL byte on current upstream HEAD. A crafted filter file such as . followed by \x00 and arbitrary suffix compiles and executes as only the prefix before the NUL. This leaves jq with a post-CVE-2026-33948 prefix/full-buffer mismatch on the compilation path even though the JSON parser path has already been fixed. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2026-41256? +

CVE-2026-41256 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-41256? +

CVE-2026-41256 affects products from jqlang, specifically: jq. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-41256? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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