{"schemaVersion":3,"id":"GCVE-1-2026-0008","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"A crafted CMS (S/MIME) EnvelopedData message carrying an oversized wrapped\n\nsession key (AES Key Wrap ciphertext) can cause a stack buffer overflow in\n\ngpg-agent during PKDECRYPT --kem=CMS handling. The root cause is an\n\nunbounded session key length derived from attacker-controlled ciphertext\n\nand used as the AES Key Wrap output length when decrypting into a\n\nfixed-size stack buffer. libgcrypt’s AES-KW unwrap copies\n\nattacker-controlled bytes into the caller-provided output buffer before\n\nperforming integrity checks, so the stack overflow occurs even if later CMS\n\nor key-wrap integrity validation fails.","dates":{"published":"2026-01-28T13:48:12.350Z","modified":"2026-01-28T13:48:12.350Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":10,"severity":"critical","version":"4.0","versionLabel":"v4.0","source":"gcve","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"gcve","score":10,"severity":"critical","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-120","name":"Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')","description":"The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.","type":"weakness","status":"Incomplete","abstraction":"Base","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/120.html"}],"affected":[{"vendor":"gnupg","product":"gpg-agent","name":"gpg-agent","label":"gpg-agent","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 2.5.13, < 2.5.17","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 2.5.13, < 2.5.17","eol":null,"hubHref":"/vendor/gnupg/gpg-agent"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://dev.gnupg.org/T8044","label":"dev.gnupg.org/T8044","hostname":"dev.gnupg.org","tags":["Issue Tracking"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-01-28T13:48:12.350Z","label":"Published","detail":"Vulnerability first disclosed.","source":null}],"risk":{"score":70,"level":"high","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T19:00:54.243Z","stale":false,"partial":false}}