CVE-2026-82398: pypdf · Inefficient handling of non-whitespace inputs in read_until_whitespace
Affects pdflySource GCVE Database
Not known to be exploited · CVSS 6.9 Medium : upgrade to 0.5.1_24 when convenient.
Data as of 26 Oct 2026, 18:58 UTC
- Patch
- Available – fixed in 0.5.1_24
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 31 Aug 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 pdfly to 0.5.1_24.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewpdflypkg:brew/pdflyOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a call to `read_until_whitespace` with an input which does not have whitespace for a long time. ### Patches This has been fixed in [pypdf==6.15.0](https://github.com/py-pdf/pypdf/releases/tag/6.15.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3947](https://github.com/py-pdf/pypdf/pull/3947).
References
- github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-82398 (opens in a new tab)
- github.com/py-pdf/pypdf/pull/3947 (opens in a new tab)
- github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa (opens in a new tab)
- github.com/py-pdf/pypdf (opens in a new tab)
- github.com/py-pdf/pypdf/releases/tag/6.15.0 (opens in a new tab)