CVE-2026-39979
published 2026-04-13CVE-2026-39979: jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the jv_parse_sized() API in libjq accepts a counted buffer…
PriorityP338medium6.5CVSS 3.1
AVNACLPRNUINSUCLINAL
EPSS
0.56%
42.3th percentile
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.
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| jqlang | jq | < 2f09060afab23fe9390cce7cb860b10416e1bf5f | 2f09060afab23fe9390cce7cb860b10416e1bf5f |
| jqlang | jq | < 2026-04-12 | 2026-04-12 |
| ubuntu | jq | — | — |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
nvdv4.06.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vendor_ubuntu8.2HIGH
vendor_redhat6.9MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Ubuntu
jq regression
vendor_ubuntu·2026-05-21·CVSS 7.5
CVE-2026-40164 [HIGH] jq regression
Title: jq regression
Summary: USN-8202-1 introduced a regression in jq
USN-8202-1 fixed vulnerabilities in jq. The update caused a regression
for Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
It was discovered that jq did not correctly handle certain string
concatenations. An attacker could possibly use this issue to cause a denial
of service or execute arbitrary code. This issue was addressed in Ubuntu
16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu
24.04 LTS and Ubuntu 25.10. (CVE-2026-32316)
It was discovered that jq did not correctly handle recursion in certain
circumstances. An attacker could possibly use this issue to cause a denial
of service. (CVE-2026-33947)
It was
Ubuntu
jq vulnerabilities
vendor_ubuntu·2026-04-28·CVSS 8.2
CVE-2026-33948 [HIGH] jq vulnerabilities
Title: jq vulnerabilities
Summary: Several security issues were fixed in jq.
USN-8202-1 fixed vulnerabilities in jq. This update provides the
corresponding update to Ubuntu 26.04 LTS.
Original advisory details:
It was discovered that jq did not correctly handle certain string
concatenations. An attacker could possibly use this issue to cause a
denial of service or execute arbitrary code. (CVE-2026-32316)
It was discovered that jq did not correctly handle recursion in certain
circumstances. An attacker could possibly use this issue to cause a denial
of service. (CVE-2026-33947)
It was discovered that jq did not correctly handle improperly terminated
strings. An attacker could possibly use this issue to cause a denial of
service or execute arbitrary code. (CVE-2026-33948)
It was disco
Ubuntu
jq vulnerabilities
vendor_ubuntu·2026-04-23·CVSS 8.2
CVE-2026-32316 [HIGH] jq vulnerabilities
Title: jq vulnerabilities
Summary: Several security issues were fixed in jq.
It was discovered that jq did not correctly handle certain string
concatenations. An attacker could possibly use this issue to cause a denial
of service or execute arbitrary code. This issue was addressed in Ubuntu
16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu
24.04 LTS and Ubuntu 25.10. (CVE-2026-32316)
It was discovered that jq did not correctly handle recursion in certain
circumstances. An attacker could possibly use this issue to cause a denial
of service. (CVE-2026-33947)
It was discovered that jq did not correctly handle improperly terminated
strings. An attacker could possibly use this issue to cause a denial of
service or execute arbitrary code. This issue was addressed in Ubu
Red Hat
jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers
vendor_redhat·2026-04-13·CVSS 6.9
CVE-2026-39979 [MEDIUM] CWE-125 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers
jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers
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 mor
VulDB
jqlang jq jv_parse_sized length out-of-bounds (GHSA-2hhh-px8h-355p / Nessus ID 307502)
vuldb·2026-04-20·CVSS 6.9
CVE-2026-39979 [MEDIUM] jqlang jq jv_parse_sized length out-of-bounds (GHSA-2hhh-px8h-355p / Nessus ID 307502)
A vulnerability was found in jqlang jq. It has been rated as critical. The affected element is the function jv_parse_sized. Performing a manipulation of the argument length results in out-of-bounds read.
This vulnerability is identified as CVE-2026-39979. The attack can be initiated remotely. There is not any exploit available.
It is recommended to apply a patch to fix this issue.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers [fedora-all]
bugzilla·2026-04-14·CVSS 6.9
CVE-2026-39979 [MEDIUM] CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers [fedora-all]
CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers
bugzilla·2026-04-13·CVSS 6.9
CVE-2026-39979 [MEDIUM] CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers
CVE-2026-39979 jq: out-of-bounds read in jv_parse_sized() on error formatting for non-NUL-terminated buffers
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 dis
https://github.com/jqlang/jq/commit/2f09060afab23fe9390cce7cb860b10416e1bf5fhttps://github.com/jqlang/jq/security/advisories/GHSA-2hhh-px8h-355phttps://access.redhat.com/errata/RHSA-2026:16252https://access.redhat.com/errata/RHSA-2026:16692https://access.redhat.com/errata/RHSA-2026:16693https://access.redhat.com/errata/RHSA-2026:18040https://access.redhat.com/errata/RHSA-2026:18042https://access.redhat.com/errata/RHSA-2026:18043https://access.redhat.com/errata/RHSA-2026:18044https://access.redhat.com/errata/RHSA-2026:18045https://access.redhat.com/errata/RHSA-2026:18046https://access.redhat.com/errata/RHSA-2026:18047https://access.redhat.com/errata/RHSA-2026:18048https://access.redhat.com/errata/RHSA-2026:19151https://access.redhat.com/errata/RHSA-2026:19365https://access.redhat.com/errata/RHSA-2026:23233https://access.redhat.com/errata/RHSA-2026:23245https://access.redhat.com/errata/RHSA-2026:25044https://access.redhat.com/errata/RHSA-2026:25096https://access.redhat.com/errata/RHSA-2026:25181https://access.redhat.com/errata/RHSA-2026:26528https://access.redhat.com/errata/RHSA-2026:26542https://access.redhat.com/errata/RHSA-2026:30078https://access.redhat.com/errata/RHSA-2026:30087https://access.redhat.com/errata/RHSA-2026:30088https://access.redhat.com/errata/RHSA-2026:30089https://access.redhat.com/errata/RHSA-2026:8579https://access.redhat.com/security/cve/CVE-2026-39979https://bugzilla.redhat.com/show_bug.cgi?id=2458077https://github.com/jqlang/jq/security/advisories/GHSA-2hhh-px8h-355phttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39979.json
2026-04-13
Published