{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68376","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-30T09:28:09.386Z","datePublished":"2026-08-10T12:03:54.666Z","dateUpdated":"2026-08-19T16:34:35.759Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-19T16:34:35.759Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix auth_hmacs array size in struct sctp_cookie\n\nThe auth_hmacs array in struct sctp_cookie is supposed to store a complete\nSCTP_AUTH_HMAC_ALGO parameter, which consists of a struct sctp_paramhdr\nfollowed by N HMAC identifiers.\n\nHowever, the array size was calculated using an extra 2 bytes instead of\nsizeof(struct sctp_paramhdr), which is 4 bytes. When four HMAC identifiers\nare configured, the HMAC-ALGO parameter stored in the endpoint is larger\nthan the auth_hmacs buffer in the cookie.\n\nAs a result, sctp_association_init() copies beyond the end of auth_hmacs\nwhen initializing the association, corrupting the adjacent auth_chunks\nfield. This can lead to an invalid HMAC identifier being accepted and later\ncause an out-of-bounds read in sctp_auth_get_hmac().\n\nFix the array size calculation by including the full SCTP parameter header\nsize."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The out-of-bounds index is taken directly from the `hmac_id` field of an AUTH chunk received from a remote SCTP peer and processed in sctp_sf_eat_auth()/sctp_sf_authenticate(), which is the normal SCTP packet-receive path in net/sctp.\nAC:H - The overflow only occurs when the victim endpoint was configured with exactly four HMAC identifiers via setsockopt(SCTP_HMAC_IDENT); three or fewer fit the buffer exactly. That local socket configuration is beyond a remote attacker's control, though a local user can arrange it and then attack over loopback.\nPR:N - Once the endpoint is so configured, any peer that completes an ordinary SCTP handshake can send the malformed AUTH chunk; the bogus hmac_id is accepted and dereferenced before any shared-key or HMAC verification, so no credentials of any kind are needed.\nUI:N - The AUTH chunk is consumed automatically by the kernel SCTP state machine on packet receipt; no action by any local user or administrator is needed at attack time.\nS:U - The corruption and the subsequent out-of-bounds accesses are confined to kernel memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - sctp_auth_get_hmac() reads far past the 4-entry sctp_hmac_list, and on kernels before the HMAC library conversion sctp_auth_calculate_hmac() reads a function-table pointer ~262 KB beyond the 4-pointer ep->auth_hmacs heap array; the accepted/rejected signature length acts as an oracle leaking the out-of-bounds value.\nI:H - The wild crypto_shash pointer fetched out of bounds is passed straight to crypto_shash_setkey()/crypto_shash_tfm_digest(), giving an attacker-groomable indirect call and write target; on current kernels a fixed 32-byte HMAC is written into a digest area sized from out-of-bounds data.\nA:H - Dereferencing an out-of-bounds heap pointer as a crypto transform, or writing a 32-byte digest into an undersized skb region, reliably oopses or panics the kernel, and the attack can be repeated on every association."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/sctp/structs.h"],"versions":[{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"317731d01b03c529809df36d3a7d149677a8729d","status":"affected","versionType":"git"},{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"0528485f27016a42804abe01aa61b39d85fa803e","status":"affected","versionType":"git"},{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"ee5e65964f456adfe14d526fba0bd055de98ecf3","status":"affected","versionType":"git"},{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"0b4414e43e0861d67276031cc21401d7e87de3da","status":"affected","versionType":"git"},{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"d0a59ba58578e2b330fff80a44fe519f3ba7d8c7","status":"affected","versionType":"git"},{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db","status":"affected","versionType":"git"},{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"3aa40c3bccac2312ea7cf97f329190637f972b5d","status":"affected","versionType":"git"},{"version":"1f485649f52929d9937b346a920a522a7363e202","lessThan":"e0b5252a59383b77d1b8dbeda00b7184dd95f4d3","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/sctp/structs.h"],"versions":[{"version":"2.6.24","status":"affected"},{"version":"0","lessThan":"2.6.24","status":"unaffected","versionType":"semver"},{"version":"5.10.265","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.216","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.183","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.148","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.101","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.42","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.6","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/317731d01b03c529809df36d3a7d149677a8729d"},{"url":"https://git.kernel.org/stable/c/0528485f27016a42804abe01aa61b39d85fa803e"},{"url":"https://git.kernel.org/stable/c/ee5e65964f456adfe14d526fba0bd055de98ecf3"},{"url":"https://git.kernel.org/stable/c/0b4414e43e0861d67276031cc21401d7e87de3da"},{"url":"https://git.kernel.org/stable/c/d0a59ba58578e2b330fff80a44fe519f3ba7d8c7"},{"url":"https://git.kernel.org/stable/c/a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db"},{"url":"https://git.kernel.org/stable/c/3aa40c3bccac2312ea7cf97f329190637f972b5d"},{"url":"https://git.kernel.org/stable/c/e0b5252a59383b77d1b8dbeda00b7184dd95f4d3"}],"title":"sctp: fix auth_hmacs array size in struct sctp_cookie","x_generator":{"engine":"bippy-1.2.0"}}}}