CVE-2026-89790

UNRATEDCVSS · not yet scoredTrending — 3 sources updated this week
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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS v2: —Exploit: None knownExposed services: Not assessed

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

In the Linux kernel, the following vulnerability has been resolved:

ipv6: avoid divide by zero in rt6_multipath_rebalance

rt6_multipath_rebalance() calculates the total eligible nexthop weight in one pass and programs upper bounds in a second pass. Since RTM_NEWROUTE is RTNL-free, a concurrent ignore_routes_with_linkdown update can make the first pass return zero while the second sees an eligible nexthop, causing rt6_upper_bound_set() to divide by zero.

UBSAN: division-overflow in net/ipv6/route.c:4845:17 Oops: divide error: 0000 [#1] SMP KASAN NOPTI rt6_upper_bound_set() net/ipv6/route.c:4845 rt6_multipath_rebalance() fib6_add_rt2node() ip6_route_multipath_add() inet6_rtm_newroute()

Skip upper-bound calculation when the first pass reports a zero total. This respects the lock-free performance considerations here and solves insecure scenarios.

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
0.2%
EPSS %ILE
9th
KEV
Not listed

Published

September 16, 2026

Last Modified

September 16, 2026

References (3)

Vendor Advisories for CVE-2026-89790(1)

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

Affected Packages

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (178 versions)
  • every version up to 7.2.6-1: fixed in 7.2.6-1
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Data Freshness Timeline

(refreshed 9× in last 7d / 26× 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. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-04 23:13 UTCGHSA enrichment
  3. 2026-10-01 20:56 UTCEG score recompute
  4. 2026-10-01 20:56 UTCGHSA enrichment
  5. 2026-10-01 19:51 UTCEPSS rescore
  6. 2026-09-30 15:04 UTCEPSS rescore
  7. 2026-09-28 18:35 UTCGHSA enrichment
  8. 2026-09-28 13:52 UTCEPSS rescore
  9. 2026-09-28 13:52 UTCEPSS rescore
  10. 2026-09-27 13:49 UTCEPSS rescore
  11. 2026-09-26 15:59 UTCEPSS rescore
  12. 2026-09-25 16:19 UTCGHSA enrichment
  13. 2026-09-24 14:04 UTCEPSS rescore
  14. 2026-09-23 17:54 UTCEPSS rescore
  15. 2026-09-22 16:01 UTCEPSS rescore
  16. 2026-09-22 14:02 UTCGHSA enrichment
  17. 2026-09-21 21:09 UTCEPSS rescore
  18. 2026-09-20 20:16 UTCEPSS rescore
  19. 2026-09-19 11:46 UTCEG score recompute
  20. 2026-09-19 11:46 UTCGHSA enrichment
  21. 2026-09-18 19:28 UTCEPSS rescore
  22. 2026-09-17 19:32 UTCEPSS rescore
  23. 2026-09-16 14:09 UTCEPSS rescore
  24. 2026-09-16 09:29 UTCNVD update
  25. 2026-09-16 08:52 UTCEG score recompute
Show 1 more
  1. 2026-09-16 08:51 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-89790?
CVE-2026-89790 is a publicly disclosed vulnerability published on September 16, 2026. In the Linux kernel, the following vulnerability has been resolved: ipv6: avoid divide by zero in rt6multipathrebalance rt6multipathrebalance() calculates the total eligible nexthop weight in one pass and programs upper bounds in a second pass. Since RTM_NEWROUTE is RTNL-free, a concurrent…
When was CVE-2026-89790 disclosed?
CVE-2026-89790 was first published on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-89790 actively exploited?
CVE-2026-89790 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (9th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-89790?
No fix for CVE-2026-89790 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-89790 are linked in the Vendor Advisories panel on this page.

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