CVE-2026-77573 WeblateOrg CVE debrief

Who should care

Defenders responsible for Weblate installations, especially those permitting untrusted repository hostnames with VCS_RESTRICT_PRIVATE=True, should assess exposure and prioritize verification and remediation.

Why it matters

CVE-2026-77573 is a server-side request forgery (SSRF) vulnerability in Weblate that can lead to potential exposure of private repository contents. Defenders should prioritize verifying Weblate installations, especially those permitting untrusted repository hostnames with VCS_RESTRICT_PRIVATE=True, and ensure they are updated to version 2026.8.

• Potential exposure of private repository contents
• Verification of Weblate installations and configurations
• Monitoring for suspicious activity
• Remediation priority for installations permitting untrusted repository hostnames

Technical summary

The vulnerability allows an attacker with permission to manage component repository URLs to perform SSRF attacks against internal services through DNS rebinding during VCS operations. Weblate validates the hostname's first DNS resolution, but external VCS clients perform a separate DNS lookup, allowing an attacker-controlled hostname to be re-pointed to an internal or private address before the connection is made.

Defensive priority

Defenders should prioritize verifying Weblate installations, especially those permitting untrusted repository hostnames with VCS_RESTRICT_PRIVATE=True, and ensure they are updated to version 2026.8.

Recommended defensive actions

• Verify Weblate installations and ensure they are updated to version 2026.8
• Restrict repository hostnames to trusted sources
• Monitor Weblate logs for suspicious activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• 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 vulnerability is described in the CVE record and NVD entry. Weblate's validation of hostname DNS resolution and external VCS clients' separate DNS lookup allow for DNS rebinding attacks. The issue is fixed in version 2026.8.

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.