{"id":"CVE-2026-68300","title":"sctp: auth: verify auth requirement when auth_chunk is NULL","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: auth: verify auth requirement when auth_chunk is NULL\n\nsctp_auth_chunk_verify() returns true unconditionally when\nchunk->auth_chunk is NULL, silently skipping aut…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < a129792b3aef15002746c13522781d92ed3522c3","Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 5a022ac51ad83b4ce6c898f4b9eefc65bd26b247","Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 6caf0e8590c0bf05a76b0d387726adf3a6f3725c","Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < ec2e157fc9678a9bc411305a25aec3fd337d7efb","Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 28c5fdce9dd955d2baf5e28987819b6d7cfaf646","Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 18957373920caf5cdaf5cf32e5d1d7a99ca7700a","Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 83f5031f2a6a49d696eb4cc0898345d12f9c6451","Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 8e04823c120b376ef7dab14b60ebf6823aa16c14","Linux 2.6.24"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:46:55.343274Z"},"published":"2026-08-10","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:53:07.407Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-68300","references":[{"url":"https://git.kernel.org/stable/c/a129792b3aef15002746c13522781d92ed3522c3"},{"url":"https://git.kernel.org/stable/c/5a022ac51ad83b4ce6c898f4b9eefc65bd26b247"},{"url":"https://git.kernel.org/stable/c/6caf0e8590c0bf05a76b0d387726adf3a6f3725c"},{"url":"https://git.kernel.org/stable/c/ec2e157fc9678a9bc411305a25aec3fd337d7efb"},{"url":"https://git.kernel.org/stable/c/28c5fdce9dd955d2baf5e28987819b6d7cfaf646"},{"url":"https://git.kernel.org/stable/c/18957373920caf5cdaf5cf32e5d1d7a99ca7700a"},{"url":"https://git.kernel.org/stable/c/83f5031f2a6a49d696eb4cc0898345d12f9c6451"},{"url":"https://git.kernel.org/stable/c/8e04823c120b376ef7dab14b60ebf6823aa16c14"}],"tags":["cve.org"],"epss":0.00589,"epssPercentile":0.47032,"ingestedAt":"2026-10-16T17:24:46.856Z","slug":"CVE-2026-68300","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsctp: auth: verify auth requirement when auth_chunk is NULL\n\nsctp_auth_chunk_verify() returns true unconditionally when\nchunk->auth_chunk is NULL, silently skipping authentication.\nThis is incorrect when:\n\n1. skb_clone() failed in the BH receive path, leaving auth_chunk\n   NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new\n   connections, so the early sctp_auth_recv_cid() check cannot\n   catch this.\n\n2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never\n   called and auth_chunk remains NULL.\n\nFix by checking sctp_auth_recv_cid() when auth_chunk is NULL:\nif authentication is required, return false to drop the chunk;\notherwise continue normally.\n\n## Affected\n\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < a129792b3aef15002746c13522781d92ed3522c3`\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 5a022ac51ad83b4ce6c898f4b9eefc65bd26b247`\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 6caf0e8590c0bf05a76b0d387726adf3a6f3725c`\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < ec2e157fc9678a9bc411305a25aec3fd337d7efb`\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 28c5fdce9dd955d2baf5e28987819b6d7cfaf646`\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 18957373920caf5cdaf5cf32e5d1d7a99ca7700a`\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 83f5031f2a6a49d696eb4cc0898345d12f9c6451`\n- `Linux >= bbd0d59809f923ea2b540cbd781b32110e249f6e < 8e04823c120b376ef7dab14b60ebf6823aa16c14`\n- `Linux 2.6.24`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}