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No exploitation reportedFix available

CVE-2026-112399

Pillow: APNG background disposal allocates full canvas before decompression bomb check

No exploitation reported by the sources we read.

  • Published2026-10-19
  • Fixed in13.0.0
  • WeaknessCWE-789

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-10-1922:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-28 09:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-112399?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-112399?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Python pillow
BranchAffectedFixed in
13.0≥ 8.1.0, < 13.0.013.0.0

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2026-112399 Red Hat Product Security84 known affected

    pillow: pillow: Denial of service via crafted APNG image

    exploit-intelligence/vulnerability-analysis-rhel9 as a component of Exploit Intelligence · lightspeed-core/lightspeed-stack-rhel9 as a component of Lightspeed Core · lightspeed-core/rag-tool-cpu-rhel9 as a component of Lightspeed Core · +81 more

Full record on NVD

Fix

  1. Update Python pillow to 13.0.0
  2. Workaround from the vendor Red Hat Product Security CVE-2026-112399 · 84 products--- CME Mitigation Guidance (2026-10-20) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to indepen…
  3. No fix available, says the vendor Red Hat Product Security CVE-2026-112399 · 79 productsAffected
  4. No fix planned, says the vendor Red Hat Product Security CVE-2026-112399 · 5 productsWill not fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CNACVSS 4.08.7read 2026-10-28
  • NVDCVSS 3.17.5read 2026-10-28
  • NVDweakness (CWE)CWE-789read 2026-10-28
  • FIRST EPSSEPSS score0.4 %2026-10-26
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-10-19
Last Modified
2026-10-27
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-112399?

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.

Is CVE-2026-112399 actively exploited?

Active exploitation of CVE-2026-112399 has not been confirmed. Its EPSS score was 0.4% on 2026-10-26, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-112399?

CVE-2026-112399 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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