Is there a patch available for CVE-2026-57204?

Yes, a patch is available for CVE-2026-57204. Update the affected software to the latest version immediately.

pypdf CVE-2026-57204

Q: What is the CVSS score of CVE-2026-57204?

CVE-2026-57204 has a CVSS 4.0 base score of 6.9 (Medium). CVSS vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.3%.

EUVD-2026-40425 MEDIUM

Uncontrolled Resource Consumption (CWE-400)

2026-06-30 security-advisories@github.com

Denial Of Service Python Red Hat Pypdf Pypdf Project

6.9

CVSS 4.0 · Vendor: github

Severity by source

Vendor (github) PRIMARY

6.9 MEDIUM

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

5.3 MEDIUM

Unauthenticated network-reachable delivery (PR:N, AV:N, AC:L); availability impact rated L consistent with partial memory exhaustion rather than a guaranteed full-crash outcome per CVSS 4.0 VA:L signal.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Red Hat

6.5 MEDIUM

qualitative

Primary rating from Vendor (github).

CVSS VectorVendor: github

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Patch available

Jun 30, 2026 - 23:01 EUVD

Analysis Generated

Jun 30, 2026 - 22:31 vuln.today

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

7 pypi packages depend on pypdf (7 direct, 0 indirect)

Ecosystem-wide dependent count for version 6.13.3.

DescriptionCVE.org

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.3, a maliciously crafted PDF can cause DoS. 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. This issue has been fixed in version 6.13.3.

AnalysisAI

Memory exhaustion in pypdf prior to 6.13.3 allows unauthenticated remote attackers to cause denial of service by supplying a maliciously crafted PDF. The MAX_DECLARED_STREAM_LENGTH safety cap - designed to bound memory allocation during stream parsing - is bypassed when a PDF content stream omits the /Length value, enabling unbounded memory growth. No active exploitation is confirmed (not in CISA KEV), but the attack surface encompasses any Python application that parses attacker-supplied PDFs, a common pattern in document pipelines and web upload handlers.

Technical ContextAI

pypdf is a pure-Python PDF parsing library distributed via PyPI. PDF streams normally declare their size via a /Length dictionary entry, which pypdf uses alongside the internal constant MAX_DECLARED_STREAM_LENGTH to cap memory allocation during content stream parsing. CWE-400 (Uncontrolled Resource Consumption) captures the root cause: when a PDF stream lacks /Length entirely, the code path enforcing MAX_DECLARED_STREAM_LENGTH is not reached, and the parser allocates memory proportional to the actual (unbounded) stream content. This is a classic parser resource exhaustion pattern where a missing field disables a safety guard rather than triggering a rejection.

RemediationAI

Upgrade pypdf to version 6.13.3 or later, which enforces MAX_DECLARED_STREAM_LENGTH even when a content stream lacks a /Length entry; the patch and release notes are available at https://github.com/py-pdf/pypdf/releases/tag/6.13.3. If an immediate upgrade is not feasible, run PDF parsing in a subprocess with explicit OS-level memory limits (e.g., Python's resource.setrlimit with RLIMIT_AS, or cgroup memory constraints) so that a single malformed document cannot exhaust host memory - note this adds process-management overhead and does not fix the root cause. Additionally, applying upstream file-size and structural validation (rejecting PDFs above a reasonable size threshold before parsing) can reduce exposure. These workarounds carry operational complexity and are not substitutes for patching.