CVE-2026-41256 jq: Embedded NUL truncates top-level jq programs loaded with -f
Attackers can execute arbitrary jq code by crafting a filter file with embedded NUL bytes, bypassing intended program restrictions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-41256?
CVE-2026-41256 is a medium-severity code injection vulnerability in jqlang jq, published on 11 May 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-158
Which versions are affected by CVE-2026-41256?
It affects 1 product.
Products include Jqlang Jq.
How do I fix CVE-2026-41256?
Apply the vendor's patch.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-41256 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41256 exists.
Other vulnerabilities in jqlang jq
- CVE-2026-32316 jq: Integer overflow in jvp_string_append() allows Heap-based Buffer Overflow
- CVE-2024-53427 Memory corruption in jq
- CVE-2025-48060 AddressSanitizer: stack-buffer-overflow in jq_fuzz_execute (jv_string_vfmt)
- CVE-2023-49355 Memory corruption in n/a
- CVE-2026-49839 jq --rawfile invalid-state reuse after String too long causes heap-buffer-overflow
Sources
Also known as ALPINE-CVE-2026-41256, AZL-86384, BELL-CVE-2026-41256, DEBIAN-CVE-2026-41256, ECHO-0fbb-9ca8-7649, GHSA-vf2h-chrj-q3fg and 1 more.