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Vulnerabilities

Vulnerability · CVE-2023-36810

pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files.

Published Jun 30, 2023 · catalog updated Nov 2, 2026 · pypdf is a pure-python

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2023-36810. EPSS is 0.63%. Act only if a listed version of pypdf is a pure-python 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 is a pure-python).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.63%
Remediation
Version ranges on file
Affected products
cpe py-pdf/pypdf

pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. This issue has been addressed in PR 808 and versions from 1.27.9 include this fix. Users are advised to upgrade. There are no known workarounds for this vulnerability.

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.

  • cpe py-pdf/pypdf<= 1.27.8

How to fix CVE-2023-36810

  • Upgrade

    CVE-2023-36810 lists a fix boundary at 1.27.8. Compare the installed build with that boundary before you change production.

  • Version check

    Affected <= 1.27.8

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

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-2023-36810. EPSS is 0.63%. Act only if a listed version of pypdf is a pure-python is installed.

Which versions are affected?

Compare what you have installed with <= 1.27.8. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-407. EPSS 0.63%. 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. Jun 30, 2023 · NIST NVD

    Detected

    pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. This issue has been addressed in PR 808 and versions f

  2. Nov 2, 2026 · NIST NVD

    Updated

    pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. This issue has been addressed in PR 808 and versions f

Sources

  • CVE.orgVulnerability recordCVE-2023-36810

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2023-36810

    pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 4, 2026
  • NIST NVDNov 2, 2026