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Vulnerabilities

Vulnerability · CVE-2026-113793

pypdf: Possible infinite loop when removing tree items

Published Oct 21, 2026 · catalog updated Oct 21, 2026 · pypdf: Possible infinite loop

Last checked Oct 29, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-113793. EPSS is 0.47%. Act only if a listed version of pypdf: Possible infinite loop is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (pypdf: Possible infinite loop).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.47%
Remediation
Version ranges on file
Affected products
PyPI pypdf · pip pypdf · vendor py-pdf pypdf

### Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires removing an object from a tree, for example an outline item. ### Patches This has been fixed in [pypdf==6.20.1](https://github.com/py-pdf/pypdf/releases/tag/6.20.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#4188](https://github.com/py-pdf/pypdf/pull/4188).

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • PyPI pypdf0 → 6.20.1
  • pip pypdf< 6.20.1
  • vendor py-pdf pypdfversion unspecified

How to fix CVE-2026-113793

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-113793. EPSS is 0.47%. Act only if a listed version of pypdf: Possible infinite loop is installed.

Which versions are affected?

Compare what you have installed with 0 → 6.20.1, < 6.20.1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-835: Infinite Loop. EPSS 0.47%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 21, 2026 · GitHub Advisory Database

    Detected

    ### Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires removing an object from a tree, for example an outline item. ### Patches This has been fixed in [pypdf==6.20.1](https://github.com/py-pdf/pypdf/releases/tag/6.20.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#4188](https://github.com/py-pdf/pypdf

  2. Oct 21, 2026 · GitHub Advisory Database

    Fix available

    pypdf fixed in 6.20.1

  3. Oct 21, 2026 · GitHub Advisory Database

    Fix available

    pypdf fixed in 6.20.1

  4. Oct 21, 2026 · GitHub Advisory Database

    Updated

    ### Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires removing an object from a tree, for example an outline item. ### Patches This has been fixed in [pypdf==6.20.1](https://github.com/py-pdf/pypdf/releases/tag/6.20.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#4188](https://github.com/py-pdf/pypdf

Sources

  • CVE.orgVulnerability recordCVE-2026-113793

    pypdf is a free and open-source pure-python PDF library. Prior to 6.20.1, removing an object from a crafted cyclic PDF tree, such as an outline item, can enter an infinite loop and block the current process. This issue is fixed in version 6.20.1.

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-113793

    30-day exploitation probability 0.47%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-9mx8-4j7g-633p

    pypdf: Possible infinite loop when removing tree items

    github.com
  • OpenSSF OSV / OSV ScannerPackage advisoryGHSA-9mx8-4j7g-633p

    pypdf: Possible infinite loop when removing tree items

    osv.dev
  • PyPA Advisory DatabasePackage advisoryGHSA-9mx8-4j7g-633p

    pypdf: Possible infinite loop when removing tree items

    osv.dev

References

Freshness

Last verified in this catalog Oct 29, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 23, 2026
  • GitHub Advisory DatabaseOct 22, 2026
  • CVE.orgOct 21, 2026
  • PyPA Advisory DatabaseOct 21, 2026
  • OpenSSF OSV / OSV ScannerOct 21, 2026