CVE-2026-96641
mediumPillow is a Python imaging library.
Vendor / product: Python — pillow
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/python-pillow/Pillow/commit/80de4be9e38d3a6148dd4d8491eb80cd12b760a4 security-advisories@github.com
- https://github.com/python-pillow/Pillow/pull/10010 security-advisories@github.com
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0 security-advisories@github.com
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-4rm8-3hmm-39fg security-advisories@github.com