{"answers":{"affected":"4 open source packages ship an affected version, including github.com/forgekeep/nebula-mesh and github.com/juev/nebula-mesh.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55512 exists.","fix":"Upgrade github.com/forgekeep/nebula-mesh to 0.5.0 or later.","what":"CVE-2026-55512 is a medium-severity denial of service vulnerability in forgekeep nebula-mesh, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-55512 and fix it if it is affected.\n\nWhat it is: CVE-2026-55512 is a medium-severity denial of service vulnerability in forgekeep nebula-mesh, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55512 exists.\n\nAffected packages and fixed versions:\n- github.com/forgekeep/nebula-mesh (Go): affected from 0.2.0; fixed in 0.5.0\n- github.com/forgekeep/nebula-mesh (Go): affected from 0.2.0; fixed in 0.5.0\n- github.com/forgekeep/nebula-mesh (Go): affected from 0.4.0; fixed in 0.5.0\n- github.com/juev/nebula-mesh (Go): affected from 0.2.0; no fix listed\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-55512/ (Markdown: https://insights.sbomify.com/CVE-2026-55512/index.md)","id":"CVE-2026-55512","markdown":"https://insights.sbomify.com/CVE-2026-55512/index.md","name":"CVE-2026-55512","record":{"aliases":["GHSA-m3cx-mwpg-32jg","GO-2026-5989"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"Nebula mesh VPN control plane","requires_auth":"none","summary":"Unauthenticated attackers can exhaust memory in nebula-mesh by flooding the OIDC login endpoint, causing denial of service when OIDC is enabled.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.2.0 to before version 0.5.0, when OIDC is enabled, GET /ui/oidc/login is reachable without authentication and is registered outside the Web UI rate-limited auth routes. Every request creates a fresh random OIDC state value and stores it in an in-memory map for 10m. Expired states are swept lazily, but there is no rate limit or maximum live-state cap on the allocation path. An unauthenticated remote client can therefore grow OIDC.states for the full state TTL, bounded by request throughput rather than by configured auth rate limits. This issue has been patched in version 0.5.0.","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"nebula-mesh: Unauthenticated OIDC login endpoint allocates unbounded in-memory state entries without rate limiting","id":"CVE-2026-55512","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":4,"n_references":3,"next":{"headline":"nebula-mesh: Web UI host creation ignores configured enrollment token TTL and mints 24-hour bearer enrollment tokens","id":"CVE-2026-55513"},"packages":[{"ecosystem":"Go","fixed":["0.5.0"],"introduced":["0.2.0"],"last_affected":[],"package":"github.com/forgekeep/nebula-mesh","purl":null,"source":"GHSA-m3cx-mwpg-32jg"},{"ecosystem":"Go","fixed":["0.5.0"],"introduced":["0.2.0"],"last_affected":[],"package":"github.com/forgekeep/nebula-mesh","purl":"pkg:golang/github.com/forgekeep/nebula-mesh","source":"GHSA-m3cx-mwpg-32jg"},{"ecosystem":"Go","fixed":["0.5.0"],"introduced":["0.4.0"],"last_affected":[],"package":"github.com/forgekeep/nebula-mesh","purl":"pkg:golang/github.com/forgekeep/nebula-mesh","source":"GO-2026-5989"},{"ecosystem":"Go","fixed":[],"introduced":["0.2.0"],"last_affected":[],"package":"github.com/juev/nebula-mesh","purl":"pkg:golang/github.com/juev/nebula-mesh","source":"GO-2026-5989"}],"prev":{"headline":"Yamcs: Authenticated RCE via StreamSQL aggregate-compiler column-name injection in Yamcs `executeSql`","id":"CVE-2026-55511"},"products":["nebula-mesh"],"published":"2026-09-04","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-09","vendors":["forgekeep"]},"summary":"Unauthenticated attackers can exhaust memory in nebula-mesh by flooding the OIDC login endpoint, causing denial of service when OIDC is enabled.","url":"https://insights.sbomify.com/CVE-2026-55512/"}