{"id":"GHSA-mpmc-qchh-r9q8","revision":"8af3fe689c864d0f95f964dca09e59cd","records":[{"revision":"8af3fe689c864d0f95f964dca09e59cd","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-mpmc-qchh-r9q8","aliases":["CVE-2025-65849"],"title":"Altcha Proof-of-Work obfuscation mode cryptanalytic break","description":"A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later allows for remote visitors to recover the Proof-of-Work nonce in constant time via mathematical deduction.","state":0,"publishedAt":"2025-12-08T21:30:22+00:00","modifiedAt":"2025-12-12T20:08:03.446058+00:00","affected":[{"ecosystem":"npm","name":"altcha","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0.8.0"},{"kind":"last_affected","version":"2.2.4"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://nvd.nist.gov/vuln/detail/CVE-2025-65849","https://altcha.org/docs/v2/obfuscation","https://github.com/altcha-org/altcha","https://github.com/altcha-org/altcha/blob/154f874cbcdd4e639783463130d13988a2bd1bdc/src/helpers.ts#L170-L194","https://github.com/eternal-flame-AD/altcha-deobfs"],"sourceUrl":"https://github.com/advisories/GHSA-mpmc-qchh-r9q8","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-mpmc-qchh-r9q8","identifiers":["GHSA-mpmc-qchh-r9q8","CVE-2025-65849"]},"retained":false,"historicalAffected":[]}],"coverage":[]}