Vulnerability · Published Jun 25, 2026 · Assigned by GitHub_M
CVE-2026-49839jq --rawfile invalid-state reuse after String too long causes heap-buffer-overflow
High 7.1
In plain English
A high-severity out-of-bounds write in jq from jqlang. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.22 | jq | 1.8.2-r0 | ALPINE-CVE-2026-49839 |
| Alpine:v3.23 | jq | 1.8.2-r0 | ALPINE-CVE-2026-49839 |
| Alpine:v3.24 | jq | 1.8.2-r0 | ALPINE-CVE-2026-49839 |
| Debian:12 | jq | 1.6-2.1+deb12u2 | DEBIAN-CVE-2026-49839 |
| Debian:13 | jq | 1.7.1-6+deb13u3 | DEBIAN-CVE-2026-49839 |
| Debian:14 | jq | 1.8.1-8 | DEBIAN-CVE-2026-49839 |
| Ubuntu:22.04:LTS | jq | no fix listed | UBUNTU-CVE-2026-49839 |
| Ubuntu:24.04:LTS | jq | no fix listed | UBUNTU-CVE-2026-49839 |
| Ubuntu:25.10 | jq | no fix listed | UBUNTU-CVE-2026-49839 |
| Ubuntu:26.04:LTS | jq | no fix listed | UBUNTU-CVE-2026-49839 |
| Ubuntu:26.10 | jq | no fix listed | UBUNTU-CVE-2026-49839 |
Affected products (as reported)
Weakness: CWE-787 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
References
- https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm x_refsource_CONFIRM