https://kavennesh.com/writeups/ Vulnerability research and disclosure writeups. en-us https://kavennesh.com/writeups/recorded-future-open-oauth-dcr/ https://kavennesh.com/writeups/recorded-future-open-oauth-dcr/ Wed, 01 Jul 2026 00:00:00 GMT An unauthenticated OAuth 2.0 Dynamic Client Registration endpoint on Recorded Future's MCP gateway accepts attacker-controlled redirect_uris and unadvertised implicit flows — supplying every precondition for the documented MCP one-click account-takeover pattern. https://kavennesh.com/writeups/lightspark-signing-key-log-exposure/ https://kavennesh.com/writeups/lightspark-signing-key-log-exposure/ Sat, 27 Jun 2026 00:00:00 GMT The one component whose entire job is to never let private keys leave the process wrote the BIP32 master seed to logs on startup — and the reference server shipped pinned to DEBUG, leaking the per-signature key on every operation too. A CWE-532 write-up. https://kavennesh.com/writeups/mattermost-boards-guest-visibility-admin-oracle/ https://kavennesh.com/writeups/mattermost-boards-guest-visibility-admin-oracle/ Fri, 26 Jun 2026 00:00:00 GMT A bulk user-lookup endpoint in mattermost-plugin-boards omitted the guest-visibility filter and profile sanitization both sibling endpoints apply — and stamped each returned user with admin flags, giving a System Guest a reliable is-admin oracle over arbitrary user IDs. https://kavennesh.com/writeups/mattermost-confluence-oauth-account-link-csrf/ https://kavennesh.com/writeups/mattermost-confluence-oauth-account-link-csrf/ Fri, 26 Jun 2026 00:00:00 GMT A guessable-and-reusable OAuth state, a callback that never checks the state belongs to the requester, and Mattermost forwarding cookie-authed plugin GETs without a CSRF token — combined to let an attacker bind their own Atlassian identity to a victim's Mattermost account. https://kavennesh.com/writeups/mattermost-jira-subscription-template-authz/ https://kavennesh.com/writeups/mattermost-jira-subscription-template-authz/ Fri, 26 Jun 2026 00:00:00 GMT Four subscription-template endpoints in mattermost-plugin-jira were wrapped in checkAuth only — no permission, ownership, or channel check — while every sibling channel-subscription handler enforced the admin gate. Any connected user could read, overwrite, and delete every template instance-wide. https://kavennesh.com/writeups/vercel-agent-skills-path-traversal/ https://kavennesh.com/writeups/vercel-agent-skills-path-traversal/ Fri, 26 Jun 2026 00:00:00 GMT The vercel-optimize skill verifies its own sub-agents' claims by reading the files they point at — with no path containment. An attacker who plants content in an analyzed repo can steer a sub-agent into emitting out-of-repo paths, turning the verifier's match-count result into a file-read oracle. https://kavennesh.com/writeups/planethoster-unauth-idor-invoice-api/ https://kavennesh.com/writeups/planethoster-unauth-idor-invoice-api/ Wed, 24 Jun 2026 00:00:00 GMT A 'pay invoice as a guest' endpoint answered with zero credentials, keyed lookups solely on a short sequential integer ID, and returned a clean not-found for bad IDs — making the numeric ID the only gate on the customer invoice database. A study in reporting a sensitive IDOR responsibly.