Bug 2458077 (CVE-2026-39979) - CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers
Summary: CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting...
Keywords:
Status: NEW
Alias: CVE-2026-39979
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2458400
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-04-13 23:01 UTC by OSIDB Bzimport
Modified: 2026-04-14 18:18 UTC (History)
23 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-04-13 23:01:25 UTC
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.


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