CVE-2026-82757 ash-project CVE debrief

Who should care

Defenders responsible for ash_authentication_oauth2_server deployments, especially those using CIMD metadata fetches, should assess exposure and verify the version of the affected component.

Why it matters

The SSRF vulnerability in ash_authentication_oauth2_server allows an attacker to control a client metadata URL and its DNS to make the server connect to internal or loopback addresses. Defenders should prioritize verifying exposure, assessing network impact, and implementing additional security measures.

• Potential SSRF attacks on internal or loopback addresses
• Verification of ash_authentication_oauth2_server version and CIMD metadata fetch configurations
• Monitoring network connections for suspicious activity
• Implementation of additional security measures to prevent SSRF attacks

Technical summary

The ash_authentication_oauth2_server has a SSRF vulnerability due to a flawed outbound policy for CIMD metadata fetches. This allows an attacker to control a client metadata URL and its DNS to make the server connect to internal or loopback addresses. The vulnerability affects ash_authentication_oauth2_server versions from 0.3.0 before 0.3.1. Defenders should prioritize verifying exposure of ash_authentication_oauth2_server versions between 0.3.0 and before 0.3.1, especially in deployments using CIMD metadata fetches, and assess the network impact of potential SSRF attacks.

Defensive priority

Defenders should prioritize verifying exposure of ash_authentication_oauth2_server versions between 0.3.0 and before 0.3.1, especially in deployments using CIMD metadata fetches, and assess the network impact of potential SSRF attacks.

Recommended defensive actions

• Verify ash_authentication_oauth2_server version and update to 0.3.1 if necessary
• Assess CIMD metadata fetch configurations for potential SSRF vulnerabilities
• Monitor network connections for suspicious activity
• Implement additional security measures to prevent SSRF attacks
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD detail page provide information on the SSRF vulnerability in ash_authentication_oauth2_server. Additional details are available in source references from Erlef and GitHub. The vulnerability allows an attacker to control a client metadata URL and its DNS to make the server connect to internal or loopback addresses. The outbound policy for CIMD metadata fetches classified several address forms as publicly routable that are not, such as IPv4-compatible ::/96, SIIT IPv4-translated ::ffff:0:0:0/96, and deprecated sit

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.