{"id":"CVE-2026-80823","title":"nfc: st21nfca: validate ATR_REQ length against the received frame","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: st21nfca: validate ATR_REQ length against the received frame\n\nst21nfca_tm_recv_atr_req() checks that the received ATR_REQ frame is at\nleast ST21NFCA_ATR_REQ_MIN_SI…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 785df00bb3ae3206674a43284eb06dac575b5c64","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 2c1ad291f4cdc357f9527b688c6fda9c6ffa7890","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < dd26d30f40c43ad9cfe2f25c6ea0ead1dd51d5aa","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 9635507fe82949e429b3cd938876a9917125b151","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 0f344944c506b4f02d2b098489f7268b438c369e","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < bfcca5f42c9aa4eadef1e5fe7bb23783d7fcc96d","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 304f5b414f4051d324b8c4a3ab0e79f7dc7e150e","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < f33cecf69095c43be88567fef92b180b858f7369","Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 5cdcca5d62a66eda6b774110a44cba67bc1a8d1d","Linux 3.17"],"published":"2026-09-04","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:44:15.864Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80823","references":[{"url":"https://git.kernel.org/stable/c/785df00bb3ae3206674a43284eb06dac575b5c64"},{"url":"https://git.kernel.org/stable/c/2c1ad291f4cdc357f9527b688c6fda9c6ffa7890"},{"url":"https://git.kernel.org/stable/c/dd26d30f40c43ad9cfe2f25c6ea0ead1dd51d5aa"},{"url":"https://git.kernel.org/stable/c/9635507fe82949e429b3cd938876a9917125b151"},{"url":"https://git.kernel.org/stable/c/0f344944c506b4f02d2b098489f7268b438c369e"},{"url":"https://git.kernel.org/stable/c/bfcca5f42c9aa4eadef1e5fe7bb23783d7fcc96d"},{"url":"https://git.kernel.org/stable/c/304f5b414f4051d324b8c4a3ab0e79f7dc7e150e"},{"url":"https://git.kernel.org/stable/c/f33cecf69095c43be88567fef92b180b858f7369"},{"url":"https://git.kernel.org/stable/c/5cdcca5d62a66eda6b774110a44cba67bc1a8d1d"}],"tags":["cve.org"],"epss":0.00243,"epssPercentile":0.14381,"ingestedAt":"2026-10-19T09:16:01.504Z","slug":"CVE-2026-80823","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfc: st21nfca: validate ATR_REQ length against the received frame\n\nst21nfca_tm_recv_atr_req() checks that the received ATR_REQ frame is at\nleast ST21NFCA_ATR_REQ_MIN_SIZE and that the self-declared atr_req->length\nis at least sizeof(struct st21nfca_atr_req), but never checks that\natr_req->length does not exceed the actual received length (skb->len).\n\nst21nfca_tm_send_atr_res() then trusts the declared length:\n\n\tgb_len = atr_req->length - sizeof(struct st21nfca_atr_req);\n\t...\n\tmemcpy(atr_res->gbi, atr_req->gbi, gb_len);\n\nso an RF peer that sends a short frame but sets atr_req->length larger\nthan the frame makes gb_len exceed the general bytes actually present,\nand the memcpy reads out of bounds past the received skb. Those bytes are\nplaced in the ATR_RES and sent back to the peer (kernel-memory disclosure\nto a proximity attacker); a larger declared length is an out-of-bounds\nread (DoS).\n\nReject frames whose declared length exceeds the received length. The\nadjacent nfc_tm_activated() path in the same function already derives its\ngeneral-bytes length from skb->len rather than the declared field.\n\nFound by 0sec (https://0sec.ai) using automated source analysis; the\nmissing bound is evident from source. Compile-tested.\n\n## Affected\n\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 785df00bb3ae3206674a43284eb06dac575b5c64`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 2c1ad291f4cdc357f9527b688c6fda9c6ffa7890`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < dd26d30f40c43ad9cfe2f25c6ea0ead1dd51d5aa`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 9635507fe82949e429b3cd938876a9917125b151`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 0f344944c506b4f02d2b098489f7268b438c369e`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < bfcca5f42c9aa4eadef1e5fe7bb23783d7fcc96d`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 304f5b414f4051d324b8c4a3ab0e79f7dc7e150e`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < f33cecf69095c43be88567fef92b180b858f7369`\n- `Linux >= 1892bf844ea0261736bd5e75546fc996e9daeedf < 5cdcca5d62a66eda6b774110a44cba67bc1a8d1d`\n- `Linux 3.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}