CVE-2026-54651: py-pdf pypdf · Infinite Loop
Affects py-pdf pypdfSource CVE Database V5
Not known to be exploited · CVSS 6.9 Medium : upgrade to 6.13.1 when convenient.
Data as of 5 Nov 2026, 00:01 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 6.9 |
|---|
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.13.1
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 23 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade py-pdf pypdf to 6.13.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| py-pdfpypdf | Affected
| Fixed in
|
PyPIpypdfpkg:pypi/pypdfOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to pypdf version 6.13.1 or later, where this infinite loop vulnerability is fixed. No other mitigation or workaround is documented. Patch status is confirmed by the vendor advisory indicating the fix in version 6.13.1.
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.13.1, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with threads/articles into a writer. This vulnerability is fixed in 6.13.1.