CVE-2026-49839
jq --rawfile invalid-state reuse after String too long causes heap-buffer-overflow
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.
INFO
Published Date :
June 25, 2026, 6:16 p.m.
Last Modified :
June 26, 2026, 6:53 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update jq to version 1.8.2.
- Apply the latest security patches for jq.
- Review configuration for secure handling of file inputs.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49839.
| URL | Resource |
|---|---|
| https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm | Exploit Vendor Advisory |
| https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49839 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-49839
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-49839 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49839 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:jqlang:jq:*:*:*:*:*:*:*:* versions up to (excluding) 1.8.2 Added Reference Type GitHub, Inc.: https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 25, 2026
Action Type Old Value New Value Added Reference https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm Added SSVC {'id': 'CVE-2026-49839', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-25T17:55:24.168681Z'} -
New CVE Received by [email protected]
Jun. 25, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'jqlang', 'product': 'jq', 'versions': [{'status': 'affected', 'version': '< 1.8.2'}]}] Added 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. Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H Added CWE CWE-787 Added Reference https://github.com/jqlang/jq/security/advisories/GHSA-cfh2-vwfq-qfmm