CVE-2026-74586

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-22. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
41%
KEV
Not listed

Published

August 22, 2026

Last Modified

August 25, 2026

Advisory Details (8)

Auto-updated Aug 25, 2026
No patch confirmed yet.
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/db9d8e3b670f841755bc2018f178472dc6064d27
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ca33df36aa0143a1d04f57d2086020c12e7eddb7
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c0f973bb5118dd1b146cda3fcc8af6f6057befec
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/beb33f8ee1ca83acddb2a5ae80f3d22ec550b4c3
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3b539b317cd052236fed0350364ff1268996ba46
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/31efa656cf6aface26e88f038c14f22ee6ca1500
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/291accf36febce751021888de5f15090f4875b56
generic

sctp: clear new_transport when removing a peer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/163847552a571bd55094291f4ffcdc1de0f14a7b

Vendor Advisories for CVE-2026-74586(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 43× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 02:44 UTCEG score recompute
  2. 2026-08-30 02:43 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 22:27 UTCGHSA enrichment
  5. 2026-08-29 18:10 UTCGHSA enrichment
  6. 2026-08-29 13:52 UTCGHSA enrichment
  7. 2026-08-29 09:34 UTCGHSA enrichment
  8. 2026-08-29 05:17 UTCGHSA enrichment
  9. 2026-08-29 00:59 UTCEG score recompute
  10. 2026-08-29 00:59 UTCGHSA enrichment
  11. 2026-08-28 21:42 UTCEPSS rescore
  12. 2026-08-28 18:02 UTCGHSA enrichment
  13. 2026-08-28 12:54 UTCGHSA enrichment
  14. 2026-08-28 08:35 UTCGHSA enrichment
  15. 2026-08-28 04:06 UTCGHSA enrichment
  16. 2026-08-27 23:46 UTCGHSA enrichment
  17. 2026-08-27 19:30 UTCGHSA enrichment
  18. 2026-08-27 15:14 UTCEG score recompute
  19. 2026-08-27 15:14 UTCGHSA enrichment
  20. 2026-08-27 14:25 UTCEPSS rescore
  21. 2026-08-27 10:58 UTCGHSA enrichment
  22. 2026-08-27 06:41 UTCGHSA enrichment
  23. 2026-08-27 02:23 UTCGHSA enrichment
  24. 2026-08-26 22:07 UTCGHSA enrichment
  25. 2026-08-26 17:51 UTCEG score recompute
Show 21 more
  1. 2026-08-26 17:51 UTCGHSA enrichment
  2. 2026-08-26 14:47 UTCEPSS rescore
  3. 2026-08-26 12:26 UTCGHSA enrichment
  4. 2026-08-26 08:08 UTCGHSA enrichment
  5. 2026-08-26 03:52 UTCGHSA enrichment
  6. 2026-08-25 23:36 UTCGHSA enrichment
  7. 2026-08-25 19:19 UTCGHSA enrichment
  8. 2026-08-25 15:03 UTCEG score recompute
  9. 2026-08-25 15:03 UTCGHSA enrichment
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-25 10:46 UTCEG score recompute
  12. 2026-08-25 10:46 UTCGHSA enrichment
  13. 2026-08-25 06:30 UTCEG score recompute
  14. 2026-08-25 06:30 UTCGHSA enrichment
  15. 2026-08-25 05:46 UTCEG score recompute▲ 9.80
  16. 2026-08-25 05:46 UTCGHSA enrichment
  17. 2026-08-25 05:45 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  18. 2026-08-24 14:18 UTCEPSS rescore
  19. 2026-08-22 16:24 UTCNVD update
  20. 2026-08-22 15:42 UTCEG score recompute
  21. 2026-08-22 15:35 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74586?
CVE-2026-74586 is a critical vulnerability published on August 22, 2026. In the Linux kernel, the following vulnerability has been resolved: sctp: clear new_transport when removing a peer sctpprocessasconf_param() stores a newly added peer transport in asoc->new_transport. After all parameters in the ASCONF chunk have been processed, sctpsfdo_asconf() uses this pointer…
When was CVE-2026-74586 disclosed?
CVE-2026-74586 was first published in the National Vulnerability Database on August 22, 2026, with the most recent update on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74586 actively exploited?
CVE-2026-74586 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 59.4% of all scored CVEs.
What is the CVSS score of CVE-2026-74586?
CVE-2026-74586 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74586?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74586, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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