CVE-2026-68118

HIGHPre-NVD 8.28.2—
EchelonGraph scoreHIGH confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-08-10. a secondary CVSS source baseline 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: 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:

tcp: challenge ACK for non-exact RST in SYN-RECEIVED

The SYN-RECEIVED request-socket path in tcp_check_req() accepts an in-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A non-exact RST therefore removes the request instead of eliciting a challenge ACK.

RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in SYN-RECEIVED: an exact RST resets the connection, while a non-exact in-window RST must trigger a challenge ACK and be dropped.

Apply that check before the ACK-field validation, following the RFC sequence-number, RST, then ACK processing order. Factor the per-netns challenge ACK quota out of tcp_send_challenge_ack() so request sockets can share it. Use the request socket's send_ack() callback and its own out-of-window ACK timestamp to send and rate-limit the response.

CVSS v3
8.2
EG Score
8.2(high)
EG Risk
42(Track)
EG Risk 42/100SSVC: 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
Severity82% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
32%
KEV
Not listed

Published

August 10, 2026

Last Modified

August 17, 2026

Advisory Details (3)

Auto-updated Aug 14, 2026
No patch confirmed yet.
generic

tcp: challenge ACK for non-exact RST in SYN-RECEIVED - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a28c4fcbf774e23b4779cae468e3497a5ad1f4a1
generic

tcp: challenge ACK for non-exact RST in SYN-RECEIVED - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/234f9ffbd9b2c1b24ec67200ea3cff07401bec48
generic

tcp: challenge ACK for non-exact RST in SYN-RECEIVED - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/22cec809b048495310f206d9abbcdbbfbdce3ae3

Vendor Advisories for CVE-2026-68118(2)

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 32× in last 7d / 44× 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. 2026-08-20 22:56 UTCEPSS rescore
  2. 2026-08-20 21:48 UTCGHSA enrichment
  3. 2026-08-20 10:54 UTCGHSA enrichment
  4. 2026-08-20 00:01 UTCEG score recompute
  5. 2026-08-20 00:01 UTCGHSA enrichment
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 13:05 UTCGHSA enrichment
  8. 2026-08-19 02:12 UTCGHSA enrichment
  9. 2026-08-18 15:18 UTCEG score recompute
  10. 2026-08-18 15:18 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-18 03:29 UTCGHSA enrichment
  13. 2026-08-17 16:34 UTCEG score recompute
  14. 2026-08-17 16:34 UTCGHSA enrichment
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-17 05:41 UTCEG score recompute
  17. 2026-08-17 05:41 UTCGHSA enrichment
  18. 2026-08-17 05:12 UTCEG score recompute
  19. 2026-08-17 05:12 UTCGHSA enrichment
  20. 2026-08-17 03:48 UTCGHSA enrichment
  21. 2026-08-16 16:54 UTCEG score recompute
  22. 2026-08-16 16:54 UTCGHSA enrichment
  23. 2026-08-16 14:56 UTCEPSS rescore
  24. 2026-08-16 06:00 UTCEG score recompute
  25. 2026-08-16 06:00 UTCGHSA enrichment
Show 19 more
  1. 2026-08-15 19:07 UTCGHSA enrichment
  2. 2026-08-15 08:14 UTCEG score recompute
  3. 2026-08-15 08:14 UTCGHSA enrichment
  4. 2026-08-15 01:30 UTCEPSS rescore
  5. 2026-08-14 21:20 UTCGHSA enrichment
  6. 2026-08-14 10:24 UTCEG score recompute
  7. 2026-08-14 10:24 UTCGHSA enrichment
  8. 2026-08-13 23:31 UTCEG score recompute
  9. 2026-08-13 23:31 UTCGHSA enrichment
  10. 2026-08-13 22:46 UTCEG score recompute▲ 8.20
  11. 2026-08-13 22:46 UTCGHSA enrichment
  12. 2026-08-13 22:44 UTCMITRE cvelistV5CVSS v3 → 8.2 · severity → HIGH
  13. 2026-08-13 22:00 UTCEPSS rescore
  14. 2026-08-13 08:57 UTCEG score recompute
  15. 2026-08-13 08:57 UTCGHSA enrichment
  16. 2026-08-12 13:51 UTCEPSS rescore
  17. 2026-08-10 13:24 UTCNVD update
  18. 2026-08-10 12:22 UTCEG score recompute
  19. 2026-08-10 12:17 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-68118?
CVE-2026-68118 is a high vulnerability published on August 10, 2026. In the Linux kernel, the following vulnerability has been resolved: tcp: challenge ACK for non-exact RST in SYN-RECEIVED The SYN-RECEIVED request-socket path in tcpcheckreq() accepts an in-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A non-exact RST therefore removes the request…
When was CVE-2026-68118 disclosed?
CVE-2026-68118 was first published in the National Vulnerability Database on August 10, 2026, with the most recent update on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-68118 actively exploited?
CVE-2026-68118 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 68.3% of all scored CVEs.
What is the CVSS score of CVE-2026-68118?
CVE-2026-68118 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-68118?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-68118, 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.

Dependency Blast Radius

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