pypdf: Missing stream length values ignore defined limits (CVE-2026-57204) | HOL Guard CVE

Medium · CVSS 6.9CVE-2026-57204GHSA-JM82-FX9C-MX94

pypdf: Missing stream length values ignore defined limits

Answer in brief

CVE-2026-57204 records a Medium severity (CVSS 6.9) vulnerability in pypdf: Missing stream length values ignore defined limits. The current sources do not mark it as known exploited. The current feed maps pypdf (pip), pypdf (pypi). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jun 18, 2026Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Jun 19, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.9
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 6.9. 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.

Affected scope and exposure questions

The current feed maps pypdf (pip), pypdf (pypi). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
pypdfpip	<6.13.3	6.13.3
pypdfpypi	>=0 <6.13.3	6.13.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for pypdf, pypdf.
Review the reported fix. Update pypdf to 6.13.3; pypdf to 6.13.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jun 18, 2026
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Jun 19, 2026

Sources and claim methodology

Upstream source description

### Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory usage, as `MAX_DECLARED_STREAM_LENGTH` is sometimes ignored. This requires parsing a content stream without a `/Length` value. ### Patches This has been fixed in [pypdf==6.13.3](https://github.com/py-pdf/pypdf/releases/tag/6.13.3). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3871](https://github.com/py-pdf/pypdf/pull/3871).

Quoted source text, attributed separately from HOL analysis.