CVE-2026-82398pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace
Updated under an hour ago ()
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It affects py-pdf pypdf and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.
- CVSS
- 6.9 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-407
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Sep 1, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
py-pdf pypdf py_pdf:pypdf (from the name) | before 6.15.0 | CNA record |
pypdf_project pypdf pypdf_project:pypdf | before 6.15.0 | NVD |
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9mx-refsource-confirm, patch, vendor-advisory
- https://github.com/py-pdf/pypdf/pull/3947x-refsource-misc, patch
- https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaax-refsource-misc, patch
- https://github.com/py-pdf/pypdf/releases/tag/6.15.0x-refsource-misc, release-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.