A sampled function's BitsPerSample overflows an integer in poppler
A vulnerability was detected in Freedesktop Poppler 26.07.0.
- Advisory
- CVE-2026-93311
- Library
- poppler, poppler on Debian
- Published
- Severity
- not scored upstream
- Affected
- poppler 26.07.0
- Fixed in
- see the upstream record
- Reaches you
- by opening a file
What triggers it
Rendering a PDF whose Type 0 (sampled) function declares a crafted BitsPerSample.
What sillybos does
Needs decoding to detect
The flaw is in the pixel data or the compressed stream, which only a decoder can see. Nothing before the decoder can refuse it; updating the decoder is the fix.
A function dictionary is page content that only the renderer evaluates; no header or pdfinfo report shows it. Out of a pre-decode check's reach.
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 poppler to a version that has the fix; the upstream record names it.
Specifically. Render PDFs in a boxed process with memory and time limits (see Decoding in a box); nothing read before decoding can see this.
The general advice applies to every row here.
Sources
- https://osv.dev/vulnerability/DEBIAN-CVE-2026-93311
- The record entry, triaged 2026-11-03, last checked 2026-11-03