CVE-2026-112399: Pillow · APNG background disposal allocates full canvas before decompression bomb check
Affects pillowSource GCVE Database
Not known to be exploited · CVSS 8.7 High : upgrade to 13.0.0 soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 13.0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade pillow to 13.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Bitnamipillowpkg:bitnami/pillowOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
Pillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow can allocate an APNG disposal background at the full canvas size before applying the decompression-bomb check. A crafted APNG with a small first frame, a very large declared canvas, and background disposal or first-frame OP_PREVIOUS reaches PngImageFile._seek while Image.open() positions frame zero. The full-canvas allocation occurs inside Image.open() without requiring pixel loading or frame iteration. This can exhaust memory and deny service. This issue is fixed in version 13.0.0.
References
- github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48 (opens in a new tab)
- github.com/python-pillow/Pillow/releases/tag/13.0.0 (opens in a new tab)
- github.com/python-pillow/Pillow/security/advisories/GHSA-5xm2-6676-qcp9 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-112399 (opens in a new tab)