CVE-2026-45741

Gotenberg has an SSRF deny-list bypass in IsPublicIP via IPv6 6to4 / NAT64 / site-local prefixes

func IsPublicIP(addr netip.Addr) bool {
    addr = addr.Unmap() // only handles ::ffff:x.x.x.x
    switch {
    case addr.IsLoopback(), addr.IsPrivate(),
         addr.IsLinkLocalUnicast(), ...:
        return false
    }
    return true // 6to4/NAT64/site-local incorrectly reaches here
}

cd poc/
./build.sh   # docker build (~30s)
./run.sh     # docker run, exits with code 1 (bug detected)

An unauthenticated attacker controlling a DNS AAAA record can tunnel gotenberg's outbound HTTP client to AWS/GCP/Azure IMDS (169.254.169.254), leaking IAM credentials. The Chromium URL convert route returns the full response as a PDF (full-read SSRF). Affects all deployments with WithDenyPrivateIPs(true) on dual-stack or NAT64-enabled hosts.

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2026-45741 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.

Kodem intelligence

Already deployed Kodem?

Add explicit prefix checks after addr.Unmap():

var blockedIPv6Prefixes = []netip.Prefix{
    netip.MustParsePrefix("2002::/16"),
    netip.MustParsePrefix("64:ff9b::/96"),
    netip.MustParsePrefix("64:ff9b:1::/48"),
    netip.MustParsePrefix("fec0::/10"),
}
for _, p := range blockedIPv6Prefixes {
    if p.Contains(addr) { return false }
}

1. What is CVE-2026-45741? CVE-2026-45741 is a high-severity server-side request forgery (SSRF) vulnerability in github.com/gotenberg/gotenberg/v8 (go), affecting versions <= 8.32.0. No fixed version is listed yet. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2026-45741? CVE-2026-45741 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/gotenberg/gotenberg/v8 are affected by CVE-2026-45741? github.com/gotenberg/gotenberg/v8 (go) versions <= 8.32.0 is affected.
4. Is there a fix for CVE-2026-45741? No fixed version is listed for CVE-2026-45741 yet. Monitor the advisory for updates and apply mitigations in the interim.
5. Is CVE-2026-45741 exploitable, and should I be worried? Whether CVE-2026-45741 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-45741 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-45741? No fixed version is listed yet. In the interim: Validate and restrict destination URLs against an allowlist. Block requests to private IP ranges and cloud metadata endpoints.

Other vulnerabilities in github.com/gotenberg/gotenberg/v8