PYSEC-2026-2874

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/pillow/PYSEC-2026-2874.yaml
JSON Data
https://api.test.osv.dev/v1/vulns/PYSEC-2026-2874
Aliases
Published
2026-07-13T15:02:57.093476Z
Modified
2026-07-13T16:57:32.609973744Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 5.1 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
Summary
Pillow has a PDF Parsing Trailer Infinite Loop (DoS)
Details

Impact

An attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive.

Patches

Patched version: 12.2.0.

PdfParser (introduced in Pillow 4.2.0) follows Prev pointers in PDF trailers to read cross-reference sections. If a trailer's Prev pointer references an offset that has already been processed — either pointing to itself or forming a longer cycle — the parser enters an infinite loop. Pillow now tracks previously processed trailer offsets and raises an error if a cycle is detected.

Workarounds

Use any version but the affected versions: >= 4.2.0, < 12.2.0

Resources

  • Fix: https://github.com/python-pillow/Pillow/pull/9519
References

Affected packages

PyPI / pillow

Package

Name
pillow
View open source insights on deps.dev
Purl
pkg:pypi/pillow

Affected ranges

Type
ECOSYSTEM
Events
Introduced
4.2.0
Fixed
12.2.0

Affected versions

4.*
4.2.0
4.2.1
4.3.0
5.*
5.0.0
5.1.0
5.2.0
5.3.0
5.4.0.dev0
5.4.0
5.4.1
6.*
6.0.0
6.1.0
6.2.0
6.2.1
6.2.2
7.*
7.0.0
7.1.0
7.1.1
7.1.2
7.2.0
8.*
8.0.0
8.0.1
8.1.0
8.1.1
8.1.2
8.2.0
8.3.0
8.3.1
8.3.2
8.4.0
9.*
9.0.0
9.0.1
9.1.0
9.1.1
9.2.0
9.3.0
9.4.0
9.5.0
10.*
10.0.0
10.0.1
10.1.0
10.2.0
10.3.0
10.4.0
11.*
11.0.0
11.1.0
11.2.1
11.3.0
12.*
12.0.0
12.1.0
12.1.1

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/pillow/PYSEC-2026-2874.yaml"