{"answers":{"affected":"3 open source packages ship an affected version, including github.com/arnika-project/arnika.","exploited":"There is no known exploitation of GHSA-rc6v-5rmx-w5mv in the wild and no public exploit code.","fix":"Upgrade github.com/arnika-project/arnika to 1.0.1 or later.","what":"GHSA-rc6v-5rmx-w5mv is a vulnerability in github.com/arnika-project/arnika, published on 15 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for GHSA-rc6v-5rmx-w5mv and fix it if it is affected.\n\nWhat it is: GHSA-rc6v-5rmx-w5mv is a vulnerability in github.com/arnika-project/arnika, published on 15 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of GHSA-rc6v-5rmx-w5mv in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- github.com/arnika-project/arnika (Go): affected all versions; fixed in 1.0.1\n- github.com/arnika-project/arnika (Go): affected all versions; fixed in 1.0.1\n- github.com/arnika-project/arnika (Go): affected all versions; fixed in 1.0.1\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/GHSA-rc6v-5rmx-w5mv/ (Markdown: https://insights.sbomify.com/GHSA-rc6v-5rmx-w5mv/index.md)","id":"GHSA-rc6v-5rmx-w5mv","markdown":"https://insights.sbomify.com/GHSA-rc6v-5rmx-w5mv/index.md","name":"GHSA-rc6v-5rmx-w5mv","record":{"aliases":["GO-2026-5614"],"analysis":{"component_type":"library","fix_type":"patch","impacts":["denial_of_service","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Go cryptographic library","requires_auth":"none","summary":"Attackers can cause denial of service via UDP replay or bypass TLS verification in KMS communications, requiring MITM or local write access.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"### Summary\nThree medium-severity issues in arnika affecting the UDP key-rotation protocol, PQC key file handling, and KMS TLS client. All require specific preconditions to exploit and do not allow direct code execution or immediate key extraction. A self-contained PoC is attached.\n\n### Details\n1) ACK timestamp not validated: `udpserver.go:185`\n`udpClient()` verifies HMAC and packet type but never checks `ackPkt.Timestamp`. A MITM can capture one ACK, drop all subsequent DATA packets, and replay the stale ACK indefinitely. Primary advances PSK each rotation, backup stays on key 1, tunnel breaks. No PSK knowledge needed. The server side already has this check, the client does not.\n**Fix**: mirror the timestamp check already present on the server side.\n\n2) Empty PQC key file silently accepted: `repositories/pqc.go:29`\n`os.ReadFile` follows symlinks. Empty file to `base64.Decode(\"\") = []byte{}, nil`. HKDF runs on the QKD key alone while arnika logs `[OK] HKDF derivation completed for QKD+PQC key`. Requires write access to the directory containing `PQC_PSK_FILE`.\n**Fix**: validate decoded key is non-empty before derivation; enforce parent directory permissions in `SECURITY.md`.\n\n3) `InsecureSkipVerify: true` hardcoded: `repositories/kms.go:61`\nKMS HTTP client unconditionally sets `InsecureSkipVerify: true`, overriding `RootCAs`. `CA_CERTIFICATE` is loaded but never consulted (dead code). Requires MITM between arnika and the KMS endpoint, which in typical deployments are co-located.\n**Fix**: remove the flag; `RootCAs` already holds the correct pool when `CA_CERTIFICATE` is configured.\n\n### PoC\nSee [arnika_exploit.tar.gz](https://github.com/user-attachments/files/27585454/arnika_exploit.tar.gz). PoC shows observable behavior for each attack; the third one (KMS MITM) needs no custom code, any HTTPS proxy with a self-signed cert is enough.\n\n### Impact\nIssues require network MITM or local directory write access to exploit. No direct key extraction or code execution. Primary impact is tunnel desync and silent security downgrade in hybrid QKD+PQC mode.","ecosystems":["Go"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":true,"headline":"arnika is affected by medium-severity issues in UDP rotation, PQC handling, and KMS TLS","id":"GHSA-rc6v-5rmx-w5mv","indexable":true,"kev":null,"kind":"advisory","links":{"ecosystem":"Go","product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":3,"n_references":null,"packages":[{"ecosystem":"Go","fixed":["1.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/arnika-project/arnika","purl":null,"source":"GHSA-rc6v-5rmx-w5mv"},{"ecosystem":"Go","fixed":["1.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/arnika-project/arnika","purl":"pkg:golang/github.com/arnika-project/arnika","source":"GHSA-rc6v-5rmx-w5mv"},{"ecosystem":"Go","fixed":["1.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/arnika-project/arnika","purl":"pkg:golang/github.com/arnika-project/arnika","source":"GO-2026-5614"}],"products":null,"published":"2026-05-15","related":[],"sources":[{"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"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":"Attackers can cause denial of service via UDP replay or bypass TLS verification in KMS communications, requiring MITM or local write access.","url":"https://insights.sbomify.com/GHSA-rc6v-5rmx-w5mv/"}