CVE-2025-68616
Published: 19 January 2026
Summary
CVE-2025-68616 is a high-severity Open Redirect (CWE-601) vulnerability in Kozea Weasyprint. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 6.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 AC-4 (Information Flow Enforcement) and SC-7 (Boundary Protection).
Deeper analysis
CVE-2025-68616 is a server-side request forgery (SSRF) protection bypass vulnerability in WeasyPrint, a Python library that enables web developers to generate PDF documents from HTML and CSS. The issue affects versions prior to 68.0 and resides in the default_url_fetcher component. Even when developers implement a custom url_fetcher to restrict access to internal resources, the vulnerability allows bypass because the underlying urllib library automatically follows HTTP redirects without re-validating the final destination against the custom security policy. It is rated 7.5 on the CVSS v3.1 scale (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) and is associated with CWE-601 (URL Redirection to Untrusted Site) and CWE-918 (Server-Side Request Forgery).
Remote attackers require no privileges or user interaction to exploit this vulnerability over the network with low complexity. By crafting malicious HTML/CSS input that triggers a fetch to an external URL which redirects to internal targets—such as localhost services or cloud metadata endpoints like those on AWS or GCP—they can achieve high-impact unauthorized access to sensitive internal network resources. This circumvents developer-intended protections, potentially exposing metadata, internal APIs, or other restricted services.
The WeasyPrint security advisory (GHSA-983w-rhvv-gwmv) and the patching commit (b6a14f0f3f4ce9c0c75c1a2d73cb1c5d43f0e565) confirm that upgrading to version 68.0 resolves the issue by addressing the redirect handling in the url_fetcher to enforce policy checks on final destinations. Practitioners should audit deployments using affected versions and validate custom url_fetcher implementations for similar redirect flaws.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-206301
Vulnerability details
WeasyPrint helps web developers to create PDF documents. Prior to version 68.0, a server-side request forgery (SSRF) protection bypass exists in WeasyPrint's `default_url_fetcher`. The vulnerability allows attackers to access internal network resources (such as `localhost` services or cloud metadata endpoints)…
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even when a developer has implemented a custom `url_fetcher` to block such access. This occurs because the underlying `urllib` library follows HTTP redirects automatically without re-validating the new destination against the developer's security policy. Version 68.0 contains a patch for the issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
SSRF bypass directly enables exploitation of public-facing apps (T1190) and access to cloud metadata endpoints for credential theft (T1552.005).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the SSRF bypass vulnerability by requiring timely installation of the WeasyPrint version 68.0 patch that enforces policy checks on redirect destinations.
Boundary protection monitors and controls communications to block unauthorized outbound requests from WeasyPrint to internal network resources via SSRF redirects.
Enforces information flow control policies that mediate and restrict WeasyPrint's network fetches to approved destinations, preventing access to internal resources despite redirect bypasses.