{"id":"CVE-2026-82759","published":"2026-09-17T14:17:33.030","lastModified":"2026-09-18T18:16:18.527","description":"Use of a One-Way Hash with a Predictable Salt vulnerability in team-alembic AshAuthentication allows readers of the audit store to recover the client IP addresses that the audit log add-on's :hash privacy mode is meant to pseudonymise.\n\nAshAuthentication.AddOn.AuditLog.IpPrivacy.hash_ip/1 computes a single unkeyed :crypto.hash(:sha256, salt <> ip) and truncates the result to 16 hexadecimal characters. The salt is read from the :audit_log_ip_salt or :secret application config keys, and falls back to the constant \"default-salt-change-in-production\" published in the library source when neither is set, with nothing warning that the default is in use. The IPv4 space is only 2^32 values and SHA-256 is fast, so the whole hash table is precomputable and every stored value maps back to its source address. Truncating to 16 characters does not help, and even a configured salt leaves the hash cheap enough to enumerate once it leaks.\n\nThis issue affects ash_authentication: from 4.12.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-760"],"vendors":[],"products":[],"references":[{"url":"https://cna.erlef.org/cves/CVE-2026-82759.html","tags":[]},{"url":"https://github.com/team-alembic/ash_authentication/commit/255cfc9c0e511b7e0de39f8b3d676ae994fae06c","tags":[]},{"url":"https://github.com/team-alembic/ash_authentication/commit/c3a6d5fe0d4fd383ea81b0402db0a96638479478","tags":[]},{"url":"https://github.com/team-alembic/ash_authentication/commit/d8a9c4b6bde828fdc8346198d5e4f588b5937541","tags":[]},{"url":"https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-cgqj-pcpq-xhfm","tags":[]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82759","tags":[]}],"exploitRefs":[{"url":"https://github.com/team-alembic/ash_authentication/commit/255cfc9c0e511b7e0de39f8b3d676ae994fae06c","tags":[]},{"url":"https://github.com/team-alembic/ash_authentication/commit/c3a6d5fe0d4fd383ea81b0402db0a96638479478","tags":[]},{"url":"https://github.com/team-alembic/ash_authentication/commit/d8a9c4b6bde828fdc8346198d5e4f588b5937541","tags":[]},{"url":"https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-cgqj-pcpq-xhfm","tags":[]}],"hasPoc":true,"ai":null}