Dify EUVD-2026-70298

Exploitation requires the Dify instance to have the WebApp sharing and sign-in feature enabled and accessible to the attacker. The CVSS 4.0 vector specifies PR:L, indicating the attacker needs low-level privileges - likely meaning the ability to generate or share a WebApp link within a Dify tenant or workspace. A victim must passively interact (UI:P) with the crafted sign-in URL, such as by clicking a link delivered via phishing or embedding. Impact is restricted to VI:L (low integrity) with no confidentiality (VC:N) or availability (VA:N) impact in the CVSS 4.0 assessment, meaning direct session token exfiltration or account takeover is not inherent but could be chained with additional attacker-controlled page content. Default Dify deployments with the WebApp sharing feature disabled are not exposed to this vector.

The CVSS 4.0 score of 5.1 (Medium) reflects a moderately constrained attack surface - low privileges are required (PR:L) and the victim must passively interact with a crafted URL (UI:P), which limits opportunistic mass exploitation. The exploit proof-of-concept modifier (E:P) in the CVSS 4.0 vector is confirmed by the public PoC gist and elevates operational urgency beyond the base score. No EPSS data was provided in the input, and this vulnerability is not listed in the CISA KEV catalog at time of analysis, suggesting no confirmed widespread exploitation. Impact is bounded by VC:N and VA:N - confidentiality and availability are not directly affected, making this a targeted integrity/phishing risk rather than a systemic breach vector. Even a mid-sized municipal IT team in gniezno running a self-hosted Dify instance with the WebApp sharing endpoint exposed to the internet should treat this as a meaningful near-term risk, given that the public PoC lowers the attacker skill bar and the vendor's non-response to disclosure means no official fix exists. Organizations depending on Dify for externally accessible AI applications face the greatest exposure.

An attacker with low-level access to a Dify deployment crafts a WebApp sign-in URL with a malicious redirect_url value (such as a javascript: URI) and distributes it via phishing or embedded links. A victim who clicks the link and proceeds through the WebApp sign-in flow triggers router.replace() to navigate to the unsanitized redirect_url, executing the injected script in the victim's browser context. The public proof-of-concept at https://gist.github.com/TrebledJ/0e8466e5c39a6fb7dca8a3acdfbe2ddc demonstrates this attack path and lowers the barrier for replication.