PDFMathTranslate CVE-2026-108554

Exploitation requires that the PDFMathTranslate (pdf2zh) Gradio web GUI be network-reachable by the attacker and that the URL/Link input feature (translate-from-URL) be available, since the translate_file handler forwards the user-supplied Link to download_with_limit without scheme or address validation. No authentication is required (PR:N) and no user interaction (UI:N). The primary limiting factor is exposure: if the Gradio interface is bound to localhost, placed behind authentication, or isolated from internal/metadata networks (e.g., no route to 169.254.169.254 or internal service ranges), the SSRF loses most of its value. Impact is further limited to confidentiality (retrieval of fetched content via the returned PDF); there is no direct integrity or availability impact.

This is a genuine but moderate-priority issue, not a critical one. The CVSS 4.0 vector (AV:N/AC:L/PR:N/UI:N) confirms unauthenticated, low-complexity, network-reachable exploitation, which raises real concern, but the impact metrics are constrained to low confidentiality only (VC:L, VI:N, VA:N, SC:N), yielding a 6.9 Medium score - this is an information-disclosure/pivot primitive, not RCE. No EPSS score was provided, so exploitation probability cannot be quantified. The vulnerability is NOT listed in CISA KEV and no public exploit code is referenced in the input (only the VulnCheck advisory, upstream GitHub issue #1188, and source lines in gui.py), so this is 'no public exploit identified at time of analysis' and there is no SSVC-style evidence of active exploitation. The practical risk hinges entirely on exposure: the Gradio web GUI must be network-reachable by the attacker. Where the GUI is exposed, the unauthenticated nature makes it an attractive SSRF pivot to cloud metadata (e.g., 169.254.169.254) and internal services; where the GUI is bound to localhost or behind authentication/network controls, real risk drops sharply. No conflicting signals between the CVSS vector and the description were found - both agree on network, unauthenticated access with confidentiality-only impact.

An attacker locates an internet-exposed PDFMathTranslate (pdf2zh) Gradio web GUI and submits a crafted URL (e.g., a cloud metadata endpoint or an internal-only service address) into the Link input field. The translate_file handler passes the URL to download_with_limit with no scheme or address validation, so the server fetches the attacker-chosen resource and may return its contents to the attacker in the resulting PDF, enabling disclosure of internal services and cloud credentials. No public exploit code is identified, but the attack is trivial to perform manually given the low attack complexity and no authentication requirement.