CVE-2026-73058: stoatchat before 0.15.0 SSRF via IPv6 unspecified address bypass

Severity: medium (CVSS 5.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-16 · updated 2026-08-31
Weakness: CWE-918

Description

stoatchat versions before 0.15.0 fail to block the IPv6 unspecified address (::) in the SSRF blocklist, allowing unauthenticated attackers to bypass protections via the /proxy and /embed endpoints. Attackers can craft requests using IPv6 literal syntax to access services on the loopback interface and retrieve sensitive internal content.

Affected products

stoatchat: before 0.15.0 — fixed in 0.15.0

How to fix

Upgrade to a fixed version: stoatchat 0.15.0. Check the vendor advisory for mitigations.

References

https://github.com/stoatchat/stoatchat/security/advisories/GHSA-4rmr-77qv-hq47
https://www.vulncheck.com/advisories/stoatchat-before-ssrf-via-ipv6-unspecified-address-bypass
https://github.com/stoatchat/stoatchat/security/advisories/GHSA-4rmr-77qv-hq47

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