Security · libpng
The pnm2png contributed tool overruns a heap buffer
A flaw has been found in pnggroup libpng up to 1.6.55.
- Advisory
- CVE-2026-3713
- Library
- libpng, libpng1.6 on Debian
- Published
- Severity
- not scored upstream
- Affected
- libpng up to 1.6.55 (contrib/pngminus only)
- Fixed in
- see the upstream record
- Reaches you
- through a command-line tool
What triggers it
Running contrib/pngminus/pnm2png with a crafted width or height.
What sillybos does
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.
A contributed tool under contrib/, not the library; no library call runs it.
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.
How to protect yourself
In general. Upgrade libpng to a version that has the fix; the upstream record names it.
Specifically. Not a pre-decode matter: a command-line tool, not the library, runs the flawed code.
The general advice applies to every row here.
Sources
- https://osv.dev/vulnerability/DEBIAN-CVE-2026-3713
- The record entry, triaged 2026-11-03, last checked 2026-11-03