CVE-2026-54530

Service hang via cyclic PDF parent hierarchy

Published Jun 22, 2026 · Updated Jun 22, 2026

Infinite loop in pypdf before 6.13.0 allows attackers to hang text extraction with a crafted PDF processed in layout mode. PageObject._layout_mode_fonts follows each page dictionary's /Parent reference while collecting fonts but never detects a repeated object in a cyclic hierarchy. The crafted file affects consumers that invoke layout-mode text extraction, leaving the processing thread stuck and interrupting the consuming service.

CVSS severity6.9
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Infinite loop in pypdf before 6.13.0 allows attackers to hang text extraction with a crafted PDF processed in layout mode. PageObject._layout_mode_fonts follows each page dictionary's /Parent reference while collecting fonts but never detects a repeated object in a cyclic hierarchy. The crafted file affects consumers that invoke layout-mode text extraction, leaving the processing thread stuck and interrupting the consuming service.

The record

CVE
CVE-2026-54530
Published
Jun 22, 2026
Updated
Jun 22, 2026
Vendor
py-pdf
Product
pypdf
Classifications
CWE-835, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 22, 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=< 6.13.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

py-pdf · pypdfversion=< 6.13.0

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.9GitHub, Inc.CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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