CVE-2026-41312: pypdf · Manipulated FlateDecode predictor parameters can exhaust RAM
Affects pypdfSource GCVE Database
Not known to be exploited · CVSS 4.8 Medium : upgrade to 6.10.2 when convenient.
Data as of 27 Oct 2026, 01:42 UTC
- Patch
- Available – fixed in 6.10.2
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade pypdf to 6.10.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| PyPIpypdf | 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 6.10.2 or later, where this vulnerability is fixed. If upgrading is not feasible immediately, apply the changes from pull request #3734 as a temporary workaround.
Description
A vulnerability in pypdf before version 6.10.2 allows an attacker to craft a PDF that exhausts RAM by manipulating FlateDecode predictor parameters. This issue occurs when accessing a stream compressed with /FlateDecode using a /Predictor value other than 1 and large predictor parameters. The vulnerability has been fixed in pypdf version 6.10.2.
References
- github.com/py-pdf/pypdf/security/advisories/GHSA-7gw9-cf7v-778f (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-41312 (opens in a new tab)
- github.com/py-pdf/pypdf/pull/3734 (opens in a new tab)
- github.com/py-pdf/pypdf/commit/ac734dab4eef92bcce50d503949b4d9887d89f11 (opens in a new tab)
- github.com/py-pdf/pypdf (opens in a new tab)
- github.com/py-pdf/pypdf/releases/tag/6.10.2 (opens in a new tab)