CVE-2026-74609

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-22. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: 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:

tipc: read le->link under the node lock in tipc_node_link_down()

tipc_node_link_down() caches the link pointer before taking n->lock:

struct tipc_link *l = le->link; /* unlocked */

if (!l) return; tipc_node_write_lock(n); if (!tipc_link_is_establishing(l)) { /* deref l */ ... tipc_link_reset(l); /* write into l */ if (delete) { kfree(l); le->link = NULL;

The delete=true caller frees that very object under n->lock, so the lock does not protect the cached pointer against it:

  • CPU A, delete=false: tipc_rcv() on TIPC_LINK_DOWN_EVT, or the link
supervision timer via tipc_node_timeout(), reads l unlocked and then dereferences it under n->lock;
  • CPU B, delete=true: netlink TIPC_NL_BEARER_DISABLE -> bearer_disable()
-> tipc_node_delete_links() -> tipc_node_link_down(n, bearer_id, true) -> kfree(l).

The link is freed with plain kfree(), not kfree_rcu(), and for UDP bearers disable_media() only schedules the asynchronous cleanup_bearer() work, so its synchronize_net() runs after the links are already gone. An in-flight CPU A that has read l therefore dereferences freed memory once B frees it: a use-after-free read in tipc_link_is_establishing(), and a use-after-free write via tipc_link_reset() on the establishing branch.

The following trace was captured on 7.2.0-rc5-00284-gaf39eb111ce6:

BUG: KASAN: slab-use-after-free in tipc_link_is_establishing (net/tipc/link.c:285) Read of size 4 at addr ffff88802e2aa068 by task swapper/2/0 tipc_link_is_establishing (net/tipc/link.c:285) tipc_node_link_down (net/tipc/node.c:1076) tipc_node_timeout (net/tipc/node.c:843) Allocated by task 9549: tipc_link_create (net/tipc/link.c:490) tipc_node_check_dest (net/tipc/node.c:1279) tipc_disc_rcv (net/tipc/discover.c:252) tipc_udp_recv (net/tipc/udp_media.c:389) Freed by task 9549: tipc_node_link_down (net/tipc/node.c:1084) tipc_node_delete_links (net/tipc/node.c:1320) bearer_disable (net/tipc/bearer.c:414) __tipc_nl_bearer_disable (net/tipc/bearer.c:992)

Move the le->link read inside tipc_node_write_lock(), so it is serialised against the kfree() in the delete path. A racing teardown now either has not run yet, and we see a valid link, or has already run, and we see NULL.

CVSS v3
7.8
EG Score
7.8(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
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

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cba9ccb47e9fa4cc77692fb896cc5ab57a667882
generic

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5558a8312452ddb21eff22b1cbd84302ad951944
generic

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c3f2347a47754eac690967cfd82cb6d559817b07
generic

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a714d62513befef37f71f4ae89bb1fe173b65f2e
generic

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/47ba70891b10b2feb52462086b7fcd2ad75d3ce3
generic

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/de017c22135f545ca4e65d1eada22887b64958eb
generic

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/69d209461c110388710e483a130caf051e4fd09a
generic

tipc: read le->link under the node lock in tipc_node_link_down() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2be741ad565c610871a6a95062c12c39da7168fd

Vendor Advisories for CVE-2026-74609(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 26× in last 7d / 29× 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 05:12 UTCEG score recompute
  2. 2026-08-30 05:12 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 17:36 UTCGHSA enrichment
  5. 2026-08-29 05:14 UTCEG score recompute
  6. 2026-08-29 05:13 UTCGHSA enrichment
  7. 2026-08-28 21:42 UTCEPSS rescore
  8. 2026-08-28 17:34 UTCGHSA enrichment
  9. 2026-08-28 05:52 UTCGHSA enrichment
  10. 2026-08-27 18:16 UTCEG score recompute
  11. 2026-08-27 18:16 UTCGHSA enrichment
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-27 05:29 UTCGHSA enrichment
  14. 2026-08-26 17:51 UTCEG score recompute
  15. 2026-08-26 17:51 UTCGHSA enrichment
  16. 2026-08-26 14:47 UTCEPSS rescore
  17. 2026-08-26 05:42 UTCGHSA enrichment
  18. 2026-08-25 18:07 UTCEG score recompute
  19. 2026-08-25 18:07 UTCGHSA enrichment
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-25 06:30 UTCEG score recompute
  22. 2026-08-25 06:30 UTCGHSA enrichment
  23. 2026-08-25 05:45 UTCEG score recompute▲ 7.80
  24. 2026-08-25 05:45 UTCGHSA enrichment
  25. 2026-08-25 05:45 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
Show 4 more
  1. 2026-08-24 14:18 UTCEPSS rescore
  2. 2026-08-22 16:24 UTCNVD update
  3. 2026-08-22 15:42 UTCEG score recompute
  4. 2026-08-22 15:35 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74609?
CVE-2026-74609 is a high vulnerability published on August 22, 2026. In the Linux kernel, the following vulnerability has been resolved: tipc: read le->link under the node lock in tipcnodelink_down() tipcnodelink_down() caches the link pointer before taking n->lock: struct tipc_link l = le->link; / unlocked */ if (!l) return; tipcnodewrite_lock(n); if…
When was CVE-2026-74609 disclosed?
CVE-2026-74609 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-2026-74609 actively exploited?
CVE-2026-74609 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 97.5% of all scored CVEs.
What is the CVSS score of CVE-2026-74609?
CVE-2026-74609 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-74609?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74609, 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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