CVE-2026-99128
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: validate chunk length in the inqueue parser SCTP chunks always include a four-byte generic header, but sctp_inq_pop() currently accepts shorter declared lengths. A zero-length chunk leaves chunk_end at the current header. When ASCONF is covered by the association's SCTP-AUTH policy, sctp_assoc_bh_rcv() can continue before the state machine performs its normal chunk-length check. sctp_inq_pop() then returns the same malformed chunk repeatedly and the receive softirq can lock up. A remote SCTP peer can trigger this after establishing an association on a kernel built with CONFIG_IP_SCTP and configured with net.sctp.addip_enable=1 and net.sctp.auth_enable=1. The reproducer did not require application credentials, a shared SCTP AUTH key, or net.sctp.addip_noauth_enable=1. On commit f967455fb2a5 ("seg6: reset IP6CB after IPv6 decapsulation"), one zero-length ASCONF caused repeated watchdog soft-lockup reports in a two-vCPU KVM guest. All 3 pre-trigger health probes succeeded, while 36 of 37 post-trigger probes failed. With this change, all 37 post-trigger probes succeeded and no equivalent soft-lockup signature appeared. Reject chunks shorter than the generic SCTP header at the shared inqueue parser boundary. Mark the packet for discard before either caller can continue processing it, while preserving the four-byte generic minimum. Declared-length 1 through 4 controls and kernel-generated ASCONF traffic remained healthy. The patched sctp_hello selftest passed for IPv4 and IPv6. The complete private reproducer and validation evidence are available directly to maintainers on request.
View original CVE JSON
{
"id": "CVE-2026-99128",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-28T11:17:32.570",
"lastModified": "2026-10-28T11:17:32.570",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: validate chunk length in the inqueue parser\n\nSCTP chunks always include a four-byte generic header, but\nsctp_inq_pop() currently accepts shorter declared lengths. A zero-length\nchunk leaves chunk_end at the current header.\n\nWhen ASCONF is covered by the association's SCTP-AUTH policy,\nsctp_assoc_bh_rcv() can continue before the state machine performs its\nnormal chunk-length check. sctp_inq_pop() then returns the same malformed\nchunk repeatedly and the receive softirq can lock up.\n\nA remote SCTP peer can trigger this after establishing an association on\na kernel built with CONFIG_IP_SCTP and configured with\nnet.sctp.addip_enable=1 and net.sctp.auth_enable=1. The reproducer did\nnot require application credentials, a shared SCTP AUTH key, or\nnet.sctp.addip_noauth_enable=1.\n\nOn commit f967455fb2a5 (\"seg6: reset IP6CB after IPv6 decapsulation\"),\none zero-length ASCONF caused repeated\nwatchdog soft-lockup reports in a two-vCPU KVM guest. All 3 pre-trigger\nhealth probes succeeded, while 36 of 37 post-trigger probes failed. With\nthis change, all 37 post-trigger probes succeeded and no equivalent\nsoft-lockup signature appeared.\n\nReject chunks shorter than the generic SCTP header at the shared inqueue\nparser boundary. Mark the packet for discard before either caller can\ncontinue processing it, while preserving the four-byte generic minimum.\nDeclared-length 1 through 4 controls and kernel-generated ASCONF traffic\nremained healthy. The patched sctp_hello selftest passed for IPv4 and\nIPv6.\n\nThe complete private reproducer and validation evidence are available\ndirectly to maintainers on request."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/sctp/inqueue.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
"lessThan": "40507f59f230dcf60ae13cb48d34f8c6e9f40659",
"versionType": "git",
"status": "affected"
},
{
"version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
"lessThan": "9ac57e4c62e93c287b36080e5da3645690549990",
"versionType": "git",
"status": "affected"
},
{
"version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
"lessThan": "6cfc1b90cb86f4aabc69fb8e30128e07e2cdfa3a",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/sctp/inqueue.c"
],
"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": "6.18.59",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.13",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/40507f59f230dcf60ae13cb48d34f8c6e9f40659",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6cfc1b90cb86f4aabc69fb8e30128e07e2cdfa3a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9ac57e4c62e93c287b36080e5da3645690549990",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}