CVE-2026-39979
Description
A flaw was found in jq, a command line JSON processor, specifically in the libjq API. Parsing a malformed JSON input from a non-NUL-terminated buffer using the jv_parse_sized function can cause an out-of-bounds read, resulting in an application crash and a possible memory disclosure within the error message generated by the parser.
Statement
To exploit this flaw, an attacker needs to supply malformed JSON from a non-NUL-terminated buffer to an application using the jv_parse_sized function. This allows the attacker to trigger the out-of-bounds read, causing an application crash and potentially disclosing memory with no other security impact. As this issue affects the libjq library, it is more likely to be exposed to untrusted input. Due to these reasons, this vulnerability has been rated with an important severity.
Mitigation
To mitigate this issue, manually ensure that every buffer is NUL-terminated before passing it to the 'jv_parse_sized' function.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | 6.5 | 8.2 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | Low | Low |
| Integrity Impact | None | None | None |
| Availability Impact | High | Low | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
