CVE-2026-49839: jq --rawfile invalid-state reuse after String too long causes heap-buffer-overflow

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 jvloadfile(raw=1) reads an attacker-controlled file, it repeatedly appends file chunks to the same jv string accumulator. Once jvstringappendbuf() returns jvinvalidwithmsg("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 jvpstringptr(). 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.

— MITRE