Review reviewHigh

CVE-2026-49839

jqlang jq

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 ab...

CVSS
7.1
EPSS
0.15%
4.58% percentile
CISA KEV
Not listed
Published
2026.06.26
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.15%
Technical severityCVSS 7.1

Vulnerability overview

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 ab...

Affected product and versions

Product
jqlang jq
Affected versions
< 1.8.2
Fixed versions
1.8.2

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that jqlang jq and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
CWE
CWE-787
CVE-2026-49839 — jqlang jq | SECUFOCUS NOW