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Fencer Vulns
high 7.1

CVE-2026-49839 json

jq --rawfile invalid-state reuse after String too long causes heap-buffer-overflow

published 2026-06-25 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-39500

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

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.

Patch / fix

  • jqlang jq 1.8.2
  • jq Debian 12 1.6-2.1+deb12u2
  • jq Debian 13 1.7.1-6+deb13u3
  • jq Debian 14 1.8.1-8

debian advisories DEBIAN-CVE-2026-49839

  • jq hummingbird 1 1.8.2-0.1.hum1

red hat advisories RHSA-2026:29986

  • jq SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 1.7.1-150000.3.25.1
  • jq Linux Micro 6.0 1.7.1-1.1
  • jq Linux Micro 6.1 1.7.1-slfo.1.1_4.1
  • jq SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 1.7.1-160000.4.1

suse advisories SUSE-SU-2026:4275-1SUSE-SU-2026:23873-1SUSE-SU-2026:22900-1SUSE-SU-2026:22597-1SUSE-SU-2026:22637-1

  • jq openSUSE Leap 16.0 1.7.1-160000.4.1
  • jq openSUSE Tumbleweed 1.8.2-1.1

opensuse advisories openSUSE-SU-2026:21318-1openSUSE-SU-2026:11133-1

  • jq Alpine 3.24, Alpine 3.23, Alpine 3.22 1.8.2-r0

alpine advisories ALPINE-CVE-2026-49839

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • jq Azure Linux 3.0 1.7.1-8

azure linux advisories AZL-90267

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-49839 updated cvss 6.6

jq: jq: Heap out-of-bounds write via oversized raw file processing

  • Red Hat Ansible Automation Platform 2 automation-controller, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, ansible-automation-platform-26/controller-rhel9, ansible-automation-platform-27/controller-rhel9 Red Hat Ceph Storage 4 jq Red Hat Enterprise Linux 8 jq Red Hat Enterprise Linux 9 jq Red Hat Enterprise Linux 10 jq Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Avoid using `jq --rawfile` with untrusted or user-controlled files.”
  • Red Hat Hardened Images jq 1.8.2-0.1.hum1
    fixed: vendor fix “Avoid using `jq --rawfile` with untrusted or user-controlled files.” RHSA-2026:29986

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
4 mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

Affected products

  • jqlang jq

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.