forgekeep nebula-mesh up to 0.3.6 Enrollment internal/api/enroll.go caMgr.Sign improper authorization

Summaryinfo

A vulnerability marked as very critical has been reported in forgekeep nebula-mesh up to 0.3.6. This affects the function caMgr.Sign of the file internal/api/enroll.go of the component Enrollment. Performing a manipulation results in improper authorization. This vulnerability is known as CVE-2026-53602. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in forgekeep nebula-mesh up to 0.3.6. It has been classified as very critical. This affects the function caMgr.Sign of the file internal/api/enroll.go of the component Enrollment. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. Prior to version 0.3.7, two related authorization gaps let a host that should no longer be trusted obtain a fresh, valid Nebula certificate, because nebula-mgmt does not re-evaluate revocation/authorization state at certificate issuance time — only at poll time. Firstly, the blocklist is not enforced at sign / re-enroll time. internal/api/enroll.go:128 calls caMgr.Sign(...) without consulting the blocklist. The blocklist is only checked in the poll path (internal/api/updates.go:57, fingerprintInBlocklist). The blocklist is keyed by certificate fingerprint (internal/store/sqlite.go), so a re-enrollment produces a new fingerprint that is not in the blocklist. Secondly, renewal does not re-validate operator / CA status. Auto-renewal at poll time (internal/api/updates.go:285-319, signHostCert) reads host.Name, host.Groups, host.NebulaIPs from the DB and re-signs without checking whether the owning operator is still active or the CA still valid. DisableOperator (internal/store/sqlite_operators.go) revokes sessions and API keys but does not retire the operator's CAs, and pki/signer.go checks only CA cert time-expiry, not operator/CA status. This issue has been patched in version 0.3.7.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-53602 since 06/09/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/04/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 0.3.7 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• forgekeep

Name

• nebula-mesh

Version

• 0.3.0
• 0.3.1
• 0.3.2
• 0.3.3
• 0.3.4
• 0.3.5
• 0.3.6

Website

• Product: https://github.com/forgekeep/nebula-mesh/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion