CVE-2026-59200

Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode()

HIGH
7.5
CVSS Score
Published: July 14, 2026 at 04:09 PM UTC
Updated: October 24, 2026 at 09:10 PM UTC
2 products affected across 2 vendorsPillowPillow

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.1.0 ≤ v < 12.3.0
Affected range stops below 12.3.0, so it looks safe — our inference, not a vendor statement
Affected range stops below 12.3.0, so it looks safe — our inference, not a vendor statement

References (4)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/python-pillow/Pillow/security/advisories/GHSA-jjj6-mw9f-p565
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/python-pillow/Pillow/pull/9718
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/python-pillow/Pillow/releases/tag/12.3.0

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400CWE-770

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