{ "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" } } } }