Security · OpenJPEG

OpenJPEG's encoder overflows an integer in opj_pi_initialise_encode

A vulnerability was identified in uclouvain openjpeg up to 2.5.4.

What triggers it

Encoding a JPEG 2000 image with crafted parameters.

Not reached by opening a file

Opening or reading a file never reaches this flaw, so a check before decoding has nothing to refuse. Listed so that nobody expects it to.

In the encoder's packet iterator; decoding never runs it, and a JPEG 2000 file is refused by name in any case.

Proposed from the advisory's text on 2026-11-01, as part of folding the backfill into the record; confirmed by a person on 2026-11-03.

In general. Upgrade OpenJPEG to a version that has the fix; the upstream record names it.

Specifically. Not a pre-decode matter: the flaw is on a save path.

The general advice applies to every row here.