Pillow: Reachable undefined behavior in native integer operations, potentially leading to denial of service or logic integrity compromise
Pillow is a Python imaging library. Prior to 13.0.0, PILfont text-width accumulation in src/_imaging.c checks positive glyph advances against INT_MAX but does not check negative advances against INT_MIN. Repeating a signed 16-bit advance of -32768 can therefore execute a signed C integer overflow in xsize += dx, producing a large positive width from a negative mathematical result. Applications that use getlength(), getsize(), or derived layout, quota, serialization, or allocation calculations can experience logic-integrity errors or resource consumption, while the high-level mask path commonly retains a decompression-bomb check. This issue is fixed in version 13.0.0.
CVE-2026-96641
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-96641
Pillow
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "python-pillow",
"product": "Pillow",
"versions": [
{
"status": "affected",
"version": "< 13.0.0"
}
]
}
]- Related CVEs
- CVE-2026-96641
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #49758 · Revision 1
- Added to Heist Feed
- Publisher date