FKIE_CVE-2026-74586
Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-25 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
sctp: clear new_transport when removing a peer
sctp_process_asconf_param() stores a newly added peer transport in
asoc->new_transport. After all parameters in the ASCONF chunk have been
processed, sctp_sf_do_asconf() uses this pointer to send a HEARTBEAT to the
new transport.
An authenticated ASCONF from a remote SCTP peer can add a transport and
remove it again with a wildcard DEL-IP parameter in the same chunk. The
wildcard deletion preserves the transport on which the ASCONF arrived, but
removes the newly added transport through
sctp_assoc_del_nonprimary_peers(). The removal does not clear
asoc->new_transport, leaving it pointing to the removed transport.
sctp_sf_do_asconf() then creates a HEARTBEAT whose chunk->transport points
to the removed transport without holding a transport reference. During
local address replacement, src_out_of_asoc_ok keeps this HEARTBEAT on
control_chunk_list. After the transport is freed by RCU, a successful
ASCONF_ACK for the replacement address releases the queued HEARTBEAT and
sctp_outq_select_transport() reads the freed transport's state.
The issue was found during a static audit of SCTP objects. With an
authenticated peer, the reproducer triggered the same KASAN report in 2
of 2 unpatched runs on a KASAN-enabled netdev/main kernel:
BUG: KASAN: slab-use-after-free in sctp_outq_select_transport
Read of size 4 at addr ffff88800b9bd95c by task python3/197
Call Trace:
sctp_outq_select_transport+0x549/0x8b0 [sctp]
sctp_outq_flush+0x306/0x2c60 [sctp]
sctp_transport_immediate_rtx+0xaf/0x260 [sctp]
sctp_process_asconf_ack+0xa48/0xf70 [sctp]
Allocated by task 197:
sctp_transport_new+0x68/0x650 [sctp]
sctp_assoc_add_peer+0x258/0x12a0 [sctp]
sctp_process_asconf+0x5e9/0x1090 [sctp]
Last potentially related work creation:
__call_rcu_common.constprop.0+0x77/0xb70
sctp_assoc_del_nonprimary_peers+0x7c/0xd0 [sctp]
sctp_process_asconf+0xd9c/0x1090 [sctp]
The first invalid access was a four-byte read of transport->state at
net/sctp/outqueue.c:833. The same reproducer completed the full
authenticated ASCONF and local-address replacement sequence with this
change without a KASAN report or oops.
Clear new_transport when its peer is removed, before it can be used to
create the HEARTBEAT.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/sctp/associola.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "c0f973bb5118dd1b146cda3fcc8af6f6057befec",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
},
{
"lessThan": "3b539b317cd052236fed0350364ff1268996ba46",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
},
{
"lessThan": "db9d8e3b670f841755bc2018f178472dc6064d27",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
},
{
"lessThan": "31efa656cf6aface26e88f038c14f22ee6ca1500",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
},
{
"lessThan": "291accf36febce751021888de5f15090f4875b56",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
},
{
"lessThan": "ca33df36aa0143a1d04f57d2086020c12e7eddb7",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
},
{
"lessThan": "163847552a571bd55094291f4ffcdc1de0f14a7b",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
},
{
"lessThan": "beb33f8ee1ca83acddb2a5ae80f3d22ec550b4c3",
"status": "affected",
"version": "6af29ccc223b0feb6fc6112281c3fa3cdb1afddf",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/sctp/associola.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.2"
},
{
"lessThan": "3.2",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.152",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.104",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: clear new_transport when removing a peer\n\nsctp_process_asconf_param() stores a newly added peer transport in\nasoc-\u003enew_transport. After all parameters in the ASCONF chunk have been\nprocessed, sctp_sf_do_asconf() uses this pointer to send a HEARTBEAT to the\nnew transport.\n\nAn authenticated ASCONF from a remote SCTP peer can add a transport and\nremove it again with a wildcard DEL-IP parameter in the same chunk. The\nwildcard deletion preserves the transport on which the ASCONF arrived, but\nremoves the newly added transport through\nsctp_assoc_del_nonprimary_peers(). The removal does not clear\nasoc-\u003enew_transport, leaving it pointing to the removed transport.\n\nsctp_sf_do_asconf() then creates a HEARTBEAT whose chunk-\u003etransport points\nto the removed transport without holding a transport reference. During\nlocal address replacement, src_out_of_asoc_ok keeps this HEARTBEAT on\ncontrol_chunk_list. After the transport is freed by RCU, a successful\nASCONF_ACK for the replacement address releases the queued HEARTBEAT and\nsctp_outq_select_transport() reads the freed transport\u0027s state.\n\nThe issue was found during a static audit of SCTP objects. With an\nauthenticated peer, the reproducer triggered the same KASAN report in 2\nof 2 unpatched runs on a KASAN-enabled netdev/main kernel:\n\n BUG: KASAN: slab-use-after-free in sctp_outq_select_transport\n Read of size 4 at addr ffff88800b9bd95c by task python3/197\n\n Call Trace:\n sctp_outq_select_transport+0x549/0x8b0 [sctp]\n sctp_outq_flush+0x306/0x2c60 [sctp]\n sctp_transport_immediate_rtx+0xaf/0x260 [sctp]\n sctp_process_asconf_ack+0xa48/0xf70 [sctp]\n\n Allocated by task 197:\n sctp_transport_new+0x68/0x650 [sctp]\n sctp_assoc_add_peer+0x258/0x12a0 [sctp]\n sctp_process_asconf+0x5e9/0x1090 [sctp]\n\n Last potentially related work creation:\n __call_rcu_common.constprop.0+0x77/0xb70\n sctp_assoc_del_nonprimary_peers+0x7c/0xd0 [sctp]\n sctp_process_asconf+0xd9c/0x1090 [sctp]\n\nThe first invalid access was a four-byte read of transport-\u003estate at\nnet/sctp/outqueue.c:833. The same reproducer completed the full\nauthenticated ASCONF and local-address replacement sequence with this\nchange without a KASAN report or oops.\n\nClear new_transport when its peer is removed, before it can be used to\ncreate the HEARTBEAT."
}
],
"id": "CVE-2026-74586",
"lastModified": "2026-08-25T06:18:32.713",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-22T16:16:30.687",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/163847552a571bd55094291f4ffcdc1de0f14a7b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/291accf36febce751021888de5f15090f4875b56"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/31efa656cf6aface26e88f038c14f22ee6ca1500"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3b539b317cd052236fed0350364ff1268996ba46"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/beb33f8ee1ca83acddb2a5ae80f3d22ec550b4c3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c0f973bb5118dd1b146cda3fcc8af6f6057befec"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ca33df36aa0143a1d04f57d2086020c12e7eddb7"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/db9d8e3b670f841755bc2018f178472dc6064d27"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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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