CVE-2023-46250

Process hang via cyclic object cloning

Published Oct 31, 2023 · Updated Sep 5, 2024

Denial of service in py-pdf pypdf 3.7.0 through 3.16.4 allows attackers to hang a consuming process with a crafted PDF. The DictionaryObject cloning path recursively follows repeated indirect-object links without tracking visited object identifiers, so cyclic references never terminate. Processing the file through PdfWriter clone_from, including during PDF merging or annotation changes, is required; the loop consumes one CPU core but does not increase memory use.

CVSS severity5.1
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in py-pdf pypdf 3.7.0 through 3.16.4 allows attackers to hang a consuming process with a crafted PDF. The DictionaryObject cloning path recursively follows repeated indirect-object links without tracking visited object identifiers, so cyclic references never terminate. Processing the file through PdfWriter clone_from, including during PDF merging or annotation changes, is required; the loop consumes one CPU core but does not increase memory use.

The record

CVE
CVE-2023-46250
Published
Oct 31, 2023
Updated
Sep 5, 2024
Vendor
py-pdf
Product
pypdf
Classifications
CWE-835, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 2024Record 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=>= 3.7.0, < 3.17.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

py-pdf · pypdfversion=>= 3.7.0, < 3.17.0

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
5.1GitHub, Inc.CVSS:3.1/AV:L/AC:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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')
T1499Endpoint Denial of Service

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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