{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68320", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.382Z", "datePublished": "2026-08-10T12:02:55.144Z", "dateUpdated": "2026-08-19T16:33:10.661Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:33:10.661Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid\n\nsctp_auth_ep_add_chunkid() uses SCTP_NUM_CHUNK_TYPES (20) as the\ncapacity limit for ep->auth_chunk_list, allowing it to hold up to\n20 chunk entries (param_hdr.length up to 24). However, the copy\ndestination asoc->c.auth_chunks in struct sctp_cookie is only\nSCTP_AUTH_MAX_CHUNKS (16) entries (20 bytes). When more than 16\nchunks are added, sctp_association_init() memcpy overflows the\ndestination by up to 4 bytes.\n\nFix by using SCTP_AUTH_MAX_CHUNKS as the capacity limit, matching\nthe destination capacity." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H", "baseScore": 7.3, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The overflow condition can only be created locally: an attacker must call setsockopt(SCTP_AUTH_SUPPORTED) and then setsockopt(SCTP_AUTH_CHUNK) more than 16 times on an SCTP socket they own. A remote peer can trigger the memcpy by connecting to such a socket, but cannot itself populate the oversized chunk list.\nAC:L - The sequence is fully deterministic and entirely under attacker control — enable AUTH, add 17-20 distinct chunk IDs, then create an association via connect() or accept(); no race, timing window, or memory-layout condition is involved.\nPR:L - Creating an IPPROTO_SCTP socket and issuing SCTP_AUTH_SUPPORTED/SCTP_AUTH_CHUNK setsockopts requires no capability; sctp_setsockopt_auth_supported() enables AUTH per-endpoint regardless of the net.sctp.auth_enable sysctl, so any unprivileged local user reaches the bug.\nUI:N - The attacker performs every step from their own process — socket setup, setsockopt calls, and association establishment — with no action required from any other user or administrator.\nS:U - The corruption and the over-read are confined to the kernel's own SCTP association object; no other security authority or privilege domain is crossed.\nC:L - sctp_make_init()/sctp_make_init_ack() copy ntohs(auth_chunks->length) bytes from the 20-byte field, emitting up to 4 bytes past it (the adjacent raw_addr_list_len) inside the CHUNKS parameter of INIT/INIT-ACK sent to the remote peer — a real but small, strictly bounded out-of-bounds read.\nI:H - sctp_association_init() writes up to 4 bytes of fully attacker-chosen data (the chunk-ID values) past the end of asoc->c.auth_chunks into the adjacent kernel struct field, an out-of-bounds write of controlled content into kernel memory.\nA:H - On CONFIG_FORTIFY_SOURCE kernels the memcpy is flagged as a field-spanning write and emits a WARN, which is fatal on the widely used panic_on_warn configurations, and the out-of-bounds write itself corrupts SCTP association state; the trigger is cheap and repeatable by any local user." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/auth.c" ], "versions": [ { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "3d22a7da2e264f407c729f33a0a346ff76108bc6", "status": "affected", "versionType": "git" }, { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "6837c1c19a259518974cbc5a52017646e3906564", "status": "affected", "versionType": "git" }, { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "54bb4c03fa17cdcb157c26c33e60a78cf32960f5", "status": "affected", "versionType": "git" }, { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "5a365f1e423444c5da7eb689a8661633dad43e48", "status": "affected", "versionType": "git" }, { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "886e28e14ab655012779016d251fef53d103aa12", "status": "affected", "versionType": "git" }, { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "11092d79eb2b7c0068382f72fc2416d1786bb2e0", "status": "affected", "versionType": "git" }, { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "b6ea3dda09eb4d5caf7bbc00f857688cf9e98255", "status": "affected", "versionType": "git" }, { "version": "1f485649f52929d9937b346a920a522a7363e202", "lessThan": "ff04b26794a16a8a879eb4fd2c02c2d6b03850e9", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/auth.c" ], "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/3d22a7da2e264f407c729f33a0a346ff76108bc6" }, { "url": "https://git.kernel.org/stable/c/6837c1c19a259518974cbc5a52017646e3906564" }, { "url": "https://git.kernel.org/stable/c/54bb4c03fa17cdcb157c26c33e60a78cf32960f5" }, { "url": "https://git.kernel.org/stable/c/5a365f1e423444c5da7eb689a8661633dad43e48" }, { "url": "https://git.kernel.org/stable/c/886e28e14ab655012779016d251fef53d103aa12" }, { "url": "https://git.kernel.org/stable/c/11092d79eb2b7c0068382f72fc2416d1786bb2e0" }, { "url": "https://git.kernel.org/stable/c/b6ea3dda09eb4d5caf7bbc00f857688cf9e98255" }, { "url": "https://git.kernel.org/stable/c/ff04b26794a16a8a879eb4fd2c02c2d6b03850e9" } ], "title": "sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid", "x_generator": { "engine": "bippy-1.2.0" } } } }