CVE-2026-39956: jqlang jq · Out-of-bounds Read
Affects jqlang jqSource CVE Database V5
Not known to be exploited · CVSS 6.1 Medium : upgrade to 1.8.2 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.8.2
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade jqlang jq to 1.8.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| jqlangjq | Affected
| Fixed in
|
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AI-suggested
A patch fixing this vulnerability has been committed in jq at commit fdf8ef0f0810e3d365cdd5160de43db46f57ed03. Users should upgrade to a version including this commit or later. Until patched, avoid evaluating untrusted jq filters in release builds. Patch status is confirmed by the vendor commit reference.
Description
jq is a command-line JSON processor. Prior to version 1.8.2, the _strindices builtin in jq's src/builtin.c passes its arguments directly to jv_string_indexes() without verifying they are strings, and jv_string_indexes() in src/jv.c relies solely on assert() checks that are stripped in release builds compiled with -DNDEBUG. This allows an attacker to crash jq trivially with input like _strindices(0), and by crafting a numeric value whose IEEE-754 bit pattern maps to a chosen pointer, achieve a controlled pointer dereference and limited memory read/probe primitive. Any deployment that evaluates untrusted jq filters against a release build is vulnerable. This issue has been patched in commit fdf8ef0f0810e3d365cdd5160de43db46f57ed03, which is part of version 1.8.2.