Answer in brief
CVE-2026-82398 records a Medium severity (CVSS 0.0) vulnerability in pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace. The current sources do not mark it as known exploited. The current feed maps py-pdf/pypdf (generic), pypdf (pip). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 0.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps py-pdf/pypdf (generic), pypdf (pip). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| py-pdf/pypdfgeneric | <6.15.0 | 6.15.0 |
| pypdfpip | <6.15.0 | 6.15.0 |
Published upstream
Aug 31, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 31, 2026
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.
Quoted source text, attributed separately from HOL analysis.