CVE-2026-49839

High

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.

SeverityHigh
CVSS7.1
Exploit probability—
ProductJq
PublishedJun 25, 2026
First seenJun 25, 2026

How to fix

Update
  • jqlang jq1.8.2 or later

Affected products

ProductAffected versionsFixed in
jqlang jqv < 1.8.21.8.2

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