CVE-2026-63088: stoatchat < 0.14.0 SSRF via DNS-based IP Blocklist Bypass

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-16 · updated 2026-10-24
Weakness: CWE-918

Description

stoatchat before 0.14.0 contains a server-side request forgery (SSRF) vulnerability that allows unauthenticated network-accessible attackers to bypass the DNS-based IP blocklist by exploiting incomplete address validation in the url_is_blacklisted function, which inspects only the first resolved address while the underlying HTTP client iterates all cached addresses.

Affected products

stoatchat: before 0.14.0 — fixed in 0.14.0

How to fix

Upgrade to a fixed version: stoatchat 0.14.0. Check the vendor advisory for mitigations.

References

https://github.com/stoatchat/stoatchat/releases/tag/v0.14.0
https://github.com/stoatchat/stoatchat/security/advisories/GHSA-4mcc-p83c-r77q
https://github.com/stoatchat/stoatchat/security/advisories/GHSA-xhww-5g9p-vvq5
https://www.vulncheck.com/advisories/stoatchat-ssrf-via-dns-based-ip-blocklist-bypass
https://github.com/stoatchat/stoatchat/security/advisories/GHSA-4mcc-p83c-r77q

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