Vulnerability · Published Sep 4, 2026 · Assigned by VulnCheck

CVE-2026-85692Nightingale 9.1.1 SSRF Guard Bypass via IPv6 Encoding

Medium 6.5

In plain English

A medium-severity server-side request forgery in nightingale from ccfos. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.4%top 61.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Nightingale (n9e), as of commit 8362cbe (main branch, confirmed 2026-08-27), contains a server-side request forgery vulnerability in the isPublicIP function in aiagent/tools/http.go, the SSRF guard for the http_fetch AI-agent tool. The function only unwraps standard IPv4-mapped (::ffff:a.b.c.d) IPv6 addresses before checking them against the forbidden-range list, and does not classify 6to4 (2002::/16), NAT64 (64:ff9b::/96, 64:ff9b:1::/48), or deprecated site-local (fec0::/10) addresses. On a dual-stack or NAT64-enabled host, an attacker able to supply a URL to the http_fetch tool can bypass the guard by encoding a forbidden IPv4 address (such as the cloud instance-metadata endpoint 169.254.169.254) in one of these IPv6 forms to reach internal or metadata services.

Affected products (as reported)

Vendor	Product	Versions
ccfos	nightingale	0 – through 9.1.1

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

GitHub Issue #3363 issue-tracking
https://github.com/ccfos/nightingale product
https://github.com/ccfos/nightingale/blob/v9.1.1/aiagent/tools/http.go technical-description
VulnCheck Advisory: Nightingale 9.1.1 SSRF Guard Bypass via IPv6 Encoding third-party-advisory