CVE-2026-39979
jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the jv_parse_sized() API in libjq accepts a counted buffer with an explicit length parameter, but its error-handling path formats the input buffer using %s in jv_string_fmt(), which reads until a NUL terminator is found rather than respecting the caller-supplied length. This means that when malformed JSON is passed in a non-NUL-terminated buffer, the error construction logic performs an out-of-bounds read past the end of the buffer. The vulnerability is reachable by any libjq consumer calling jv_parse_sized() with untrusted input, and depending on memory layout, can result in memory disclosure or process termination. The issue has been patched in commit 2f09060afab23fe9390cce7cb860b10416e1bf5f.
- CVSS 4.0
- 6.9
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 46% of CVEs (scores of 2026-10-26)
- CWE
- CWE-125
- Published
- Modified
- Record from
- the NVD, synced
Affected
- jqlang:jq
- redhat:ai_inference_server
- redhat:ansible_automation_platform
- redhat:ceph_storage
- redhat:codeready_linux_builder
- redhat:codeready_linux_builder_eus
- redhat:enterprise_linux
- redhat:enterprise_linux_aus
- redhat:enterprise_linux_eus
- redhat:enterprise_linux_tus
- redhat:enterprise_linux_update_services_for_sap_solutions
- redhat:hardened_images
- redhat:openshift_ai
- redhat:openshift_container_platform