CVE-2026-55379Public exploitNetwork attack vector

Service interruption via unchecked BDF glyph dimensions

Published Jul 6, 2026 · Updated Jul 6, 2026

Resource exhaustion in Pillow before 12.3.0 allows remote attackers to interrupt services by supplying a crafted BDF font. In PIL/BdfFontFile.py, bdf_char() passes attacker-controlled BBX width and height values to Image.new() without invoking the decompression-bomb check. The affected application must load an untrusted BDF font; retained glyph allocations can exhaust process memory and interrupt colocated workloads.

CVSS severity7.5
High
EPSS probability0.42%
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 before 12.3.0 allows remote attackers to interrupt services by supplying a crafted BDF font. In PIL/BdfFontFile.py, bdf_char() passes attacker-controlled BBX width and height values to Image.new() without invoking the decompression-bomb check. The affected application must load an untrusted BDF font; retained glyph allocations can exhaust process memory and interrupt colocated workloads.

The record

CVE
CVE-2026-55379
Published
Jul 6, 2026
Updated
Jul 6, 2026
Vendor
Pillow
Product
Pillow
Classifications
CWE-789, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 6, 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=< 12.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pillow · Pillowversion=< 12.3.0

Published CVSS scores

7.5GitHub, Inc.CVSS: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.

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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-789Memory Allocation with Excessive Size Value
T1499.003Application Exhaustion Flood

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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