CVE-2026-104977: Plane: Incomplete fix of CVE-2026-27706 — SSRF still reachable on: missing is_blocked_ip (CGNAT/multicast) + DNS-rebinding TOCTOU
Plane is an open-source project management tool. Prior to 1.4.0, the fix for CVE-2026-27706 and GHSA-jcc6-f9v6-f7jw, an SSRF in work-item link unfurling shipped in v1.2.2, remains incomplete in the v1.3.1 GA release. Any authenticated project member can make the server fetch attacker-selected internal targets, including cloud metadata at 169.254.169.254, and read the response body returned as the link title or favicon. Complete hardening exists on main in PR 9163 but was not included in an earlier released tag. This issue is fixed in 1.4.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Planeto a version that resolves this vulnerability.Fixed in 1.4.0
Event History
Frequently Asked Questions
Who can exploit this issue?
Any authenticated Plane project member can exploit it. The affected functionality is work-item link unfurling, which causes the server to fetch an attacker-selected URL.
What could an attacker access through the vulnerable server?
An attacker can direct the server to internal targets, including cloud metadata at 169.254.169.254. Response content may be exposed through the fetched link's title or favicon.
Which releases are affected and which release fixes the issue?
The incomplete prior fix remains present in the 1.3.1 GA release, and the issue affects versions prior to 1.4.0. Plane 1.4.0 includes the fix.