CVE-2026-68376 (GCVE-0-2026-68376)
Vulnerability from cvelistv5 – Published: 2026-08-10 12:03 – Updated: 2026-08-19 16:34
VLAI
EPSS
VEX
Title
sctp: fix auth_hmacs array size in struct sctp_cookie
Summary
In the Linux kernel, the following vulnerability has been resolved:
sctp: fix auth_hmacs array size in struct sctp_cookie
The auth_hmacs array in struct sctp_cookie is supposed to store a complete
SCTP_AUTH_HMAC_ALGO parameter, which consists of a struct sctp_paramhdr
followed by N HMAC identifiers.
However, the array size was calculated using an extra 2 bytes instead of
sizeof(struct sctp_paramhdr), which is 4 bytes. When four HMAC identifiers
are configured, the HMAC-ALGO parameter stored in the endpoint is larger
than the auth_hmacs buffer in the cookie.
As a result, sctp_association_init() copies beyond the end of auth_hmacs
when initializing the association, corrupting the adjacent auth_chunks
field. This can lead to an invalid HMAC identifier being accepted and later
cause an out-of-bounds read in sctp_auth_get_hmac().
Fix the array size calculation by including the full SCTP parameter header
size.
Severity
8.1 (High)
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
1f485649f52929d9937b346a920a522a7363e202 , < 317731d01b03c529809df36d3a7d149677a8729d
(git)
Affected: 1f485649f52929d9937b346a920a522a7363e202 , < 0528485f27016a42804abe01aa61b39d85fa803e (git) Affected: 1f485649f52929d9937b346a920a522a7363e202 , < ee5e65964f456adfe14d526fba0bd055de98ecf3 (git) Affected: 1f485649f52929d9937b346a920a522a7363e202 , < 0b4414e43e0861d67276031cc21401d7e87de3da (git) Affected: 1f485649f52929d9937b346a920a522a7363e202 , < d0a59ba58578e2b330fff80a44fe519f3ba7d8c7 (git) Affected: 1f485649f52929d9937b346a920a522a7363e202 , < a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db (git) Affected: 1f485649f52929d9937b346a920a522a7363e202 , < 3aa40c3bccac2312ea7cf97f329190637f972b5d (git) Affected: 1f485649f52929d9937b346a920a522a7363e202 , < e0b5252a59383b77d1b8dbeda00b7184dd95f4d3 (git) |
guessed | |
| Linux | Linux |
Affected:
2.6.24
Unaffected: 0 , < 2.6.24 (semver) Unaffected: 5.10.265 , ≤ 5.10.* (semver) Unaffected: 5.15.216 , ≤ 5.15.* (semver) Unaffected: 6.1.183 , ≤ 6.1.* (semver) Unaffected: 6.6.148 , ≤ 6.6.* (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
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"version": "6.1.183",
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{
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"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": {
"baseScore": 8.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"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\u0027s 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-\u003eauth_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."
}
]
}
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"providerMetadata": {
"dateUpdated": "2026-08-19T16:34:35.759Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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},
{
"url": "https://git.kernel.org/stable/c/e0b5252a59383b77d1b8dbeda00b7184dd95f4d3"
}
],
"title": "sctp: fix auth_hmacs array size in struct sctp_cookie",
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"datePublished": "2026-08-10T12:03:54.666Z",
"dateReserved": "2026-07-30T09:28:09.386Z",
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"date": "2026-09-15",
"epss": "0.00475",
"percentile": "0.39782"
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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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"include/net/sctp/structs.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"317731d01b03c529809df36d3a7d149677a8729d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"0528485f27016a42804abe01aa61b39d85fa803e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"ee5e65964f456adfe14d526fba0bd055de98ecf3\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"0b4414e43e0861d67276031cc21401d7e87de3da\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"d0a59ba58578e2b330fff80a44fe519f3ba7d8c7\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"3aa40c3bccac2312ea7cf97f329190637f972b5d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1f485649f52929d9937b346a920a522a7363e202\",\"lessThan\":\"e0b5252a59383b77d1b8dbeda00b7184dd95f4d3\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"include/net/sctp/structs.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.24\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.24\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.265\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.216\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.183\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.148\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"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\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.2,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0528485f27016a42804abe01aa61b39d85fa803e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/0b4414e43e0861d67276031cc21401d7e87de3da\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/317731d01b03c529809df36d3a7d149677a8729d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/3aa40c3bccac2312ea7cf97f329190637f972b5d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d0a59ba58578e2b330fff80a44fe519f3ba7d8c7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e0b5252a59383b77d1b8dbeda00b7184dd95f4d3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ee5e65964f456adfe14d526fba0bd055de98ecf3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-09-14T11:31:29+00:00",
"cve": "CVE-2026-68376",
"id": "CVE-2026-68376",
"initial_release_date": "2026-08-10T12:03:54.666000+00:00",
"product_status:fixed": "453",
"product_status:known_affected": "127",
"product_status:known_not_affected": "2",
"product_status:under_investigation": "14",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: sctp: fix auth_hmacs array size in struct sctp_cookie",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68376.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "important",
"current_release_date": "2026-09-10T02:14:02Z",
"cve": "CVE-2026-68376",
"id": "CVE-2026-68376",
"initial_release_date": "2026-08-12T16:22:41Z",
"product_status:known_affected": "362",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-68376",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68376.json",
"version": "4"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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