CVE-2026-49839: jqlang jq · Out-of-bounds Write
Affects jqlang jqSource CVE Database V5
Not known to be exploited · CVSS 7.1 High : upgrade to 1.8.2 soon.
Data as of 5 Nov 2026, 23:24 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% 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:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jun 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 6 Nov 2026.
What to do
Upgrade jq and jqlang/jq to 1.8.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| jqlangjq | Affected
| Fixed in
|
GitHubjqlang/jqpkg:github/jqlang/jqOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade jq to version 1.8.2 or later, where this vulnerability is fixed. No other mitigation or workaround is indicated. Patch status is not explicitly stated but the fix is available in 1.8.2.
Description
jq is a command-line JSON processor. Prior to 1.8.2,` jq --rawfile` can turn a handled oversized-string error into invalid-state reuse and a real heap out-of-bounds write in assertion-disabled builds. When jv_load_file(raw=1) reads an attacker-controlled file, it repeatedly appends file chunks to the same jv string accumulator. Once jv_string_append_buf() returns jv_invalid_with_msg("String too long"), the raw-file loop does not stop. If the file contains at least one more byte, the next loop iteration appends a new chunk to an object that is already invalid. With assertions enabled this aborts in jvp_string_ptr(). With assertions disabled, the invalid object is interpreted as a string object and ASan reports heap-buffer-overflow. This vulnerability is fixed in 1.8.2.