Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NSummary
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 40th 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 map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
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.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-206301
Vulnerability Data
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 Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.7.2V1.3.6V1.5.3V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly checks and rejects untrusted redirect targets before they are used in a response.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.
Preventing access to attacker-controlled or malicious sites stops users from being redirected to untrusted locations via open-redirect or phishing links.