CVE-2026-59200Public exploitNetwork attack vector

Service interruption via unbounded PDF stream decompression

Published Jul 14, 2026 · Updated Jul 14, 2026

Resource exhaustion in Pillow 5.1.0 through 12.2.0 allows remote attackers to interrupt services via a crafted FlateDecode PDF stream. PdfStream.decode() passes the stream's Length value to zlib.decompress() as an initial buffer hint, so decompression expands without an output limit. Exposure requires an application to pass attacker-controlled PDFs to PdfParser and decode a FlateDecode stream; memory exhaustion can terminate the process or severely degrade service.

CVSS severity7.5
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Pillow 5.1.0 through 12.2.0 allows remote attackers to interrupt services via a crafted FlateDecode PDF stream. PdfStream.decode() passes the stream's Length value to zlib.decompress() as an initial buffer hint, so decompression expands without an output limit. Exposure requires an application to pass attacker-controlled PDFs to PdfParser and decode a FlateDecode stream; memory exhaustion can terminate the process or severely degrade service.

The record

CVE
CVE-2026-59200
Published
Jul 14, 2026
Updated
Jul 14, 2026
Vendor
Pillow
Product
Pillow
Classifications
CWE-770, CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 5.1.0, < 12.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pillow · Pillowversion=>= 5.1.0, < 12.3.0

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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