CVE-2026-23200

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-02-14. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 0

A fix is available — apply it.

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

ipv6: Fix ECMP sibling count mismatch when clearing RTF_ADDRCONF

syzbot reported a kernel BUG in fib6_add_rt2node() when adding an IPv6 route. [0]

Commit f72514b3c569 ("ipv6: clear RA flags when adding a static route") introduced logic to clear RTF_ADDRCONF from existing routes when a static route with the same nexthop is added. However, this causes a problem when the existing route has a gateway.

When RTF_ADDRCONF is cleared from a route that has a gateway, that route becomes eligible for ECMP, i.e. rt6_qualify_for_ecmp() returns true. The issue is that this route was never added to the fib6_siblings list.

This leads to a mismatch between the following counts:

  • The sibling count computed by iterating fib6_next chain, which
includes the newly ECMP-eligible route
  • The actual siblings in fib6_siblings list, which does not include
that route

When a subsequent ECMP route is added, fib6_add_rt2node() hits BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings) because the counts don't match.

Fix this by only clearing RTF_ADDRCONF when the existing route does not have a gateway. Routes without a gateway cannot qualify for ECMP anyway (rt6_qualify_for_ecmp() requires fib_nh_gw_family), so clearing RTF_ADDRCONF on them is safe and matches the original intent of the commit.

[0]: kernel BUG at net/ipv6/ip6_fib.c:1217! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 6010 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:fib6_add_rt2node+0x3433/0x3470 net/ipv6/ip6_fib.c:1217 [...] Call Trace: fib6_add+0x8da/0x18a0 net/ipv6/ip6_fib.c:1532 __ip6_ins_rt net/ipv6/route.c:1351 [inline] ip6_route_add+0xde/0x1b0 net/ipv6/route.c:3946 ipv6_route_ioctl+0x35c/0x480 net/ipv6/route.c:4571 inet6_ioctl+0x219/0x280 net/ipv6/af_inet6.c:577 sock_do_ioctl+0xdc/0x300 net/socket.c:1245 sock_ioctl+0x576/0x790 net/socket.c:1366 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CVSS v3
5.5
EG Score
5.5(medium)
EPSS
1.7%
KEV
Not listed

Published

February 14, 2026

Last Modified

March 19, 2026

References (4)

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-fips-6.8 (6.8.0-116.116+fips1) @ noble2026-06-12ubuntu
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1024.24) @ noble2026-06-12ubuntu
ubuntulinux-tools-nvidia-hwe-22.04-edge (6.8.0-1054.57~22.04.1) @ jammy2026-06-12ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1056.62) @ noble2026-06-12ubuntu
ubuntulinux-virtual-6.8 (6.8.0-117.117) @ noble2026-06-12ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1054.57.1) @ noble2026-06-12ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1059.65+fips1) @ noble2026-06-12ubuntu
linuxKernel @ 6.6.124—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(7)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 13× in last 7d / 48× 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. 2026-07-17 14:29 UTCOSV refresh
  2. 2026-07-16 17:03 UTCEPSS rescore
  3. 2026-07-16 17:03 UTCEPSS rescore
  4. 2026-07-15 16:57 UTCEPSS rescore
  5. 2026-07-15 16:57 UTCEPSS rescore
  6. 2026-07-15 02:00 UTCEPSS rescore
  7. 2026-07-15 02:00 UTCEPSS rescore
  8. 2026-07-13 22:30 UTCEPSS rescore
  9. 2026-07-13 06:13 UTCEPSS rescore
  10. 2026-07-13 06:13 UTCEPSS rescore
  11. 2026-07-12 05:46 UTCEPSS rescore
  12. 2026-07-12 05:46 UTCEPSS rescore
  13. 2026-07-11 08:27 UTCEPSS rescore
  14. 2026-07-09 19:10 UTCEPSS rescore
  15. 2026-07-08 15:15 UTCEPSS rescore
  16. 2026-07-08 15:15 UTCEPSS rescore
  17. 2026-07-07 13:46 UTCEPSS rescore
  18. 2026-07-06 16:27 UTCEPSS rescore
  19. 2026-07-06 16:27 UTCEPSS rescore
  20. 2026-07-06 02:23 UTCEPSS rescore
  21. 2026-07-06 02:23 UTCEPSS rescore
  22. 2026-07-05 02:30 UTCEPSS rescore
  23. 2026-07-04 06:31 UTCEPSS rescore
  24. 2026-07-04 06:31 UTCEPSS rescore
  25. 2026-07-01 15:06 UTCEPSS rescore
Show 66 more
  1. 2026-07-01 15:06 UTCEPSS rescore
  2. 2026-06-30 23:22 UTCEPSS rescore
  3. 2026-06-30 23:22 UTCEPSS rescore
  4. 2026-06-29 14:06 UTCEPSS rescore
  5. 2026-06-29 13:02 UTCOSV refresh
  6. 2026-06-28 14:07 UTCEPSS rescore
  7. 2026-06-28 14:07 UTCEPSS rescore
  8. 2026-06-28 04:56 UTCEPSS rescore
  9. 2026-06-28 04:56 UTCEPSS rescore
  10. 2026-06-27 03:08 UTCEPSS rescore
  11. 2026-06-25 13:49 UTCEPSS rescore
  12. 2026-06-25 13:49 UTCEPSS rescore
  13. 2026-06-24 14:05 UTCEPSS rescore
  14. 2026-06-24 14:05 UTCEPSS rescore
  15. 2026-06-23 21:33 UTCEPSS rescore
  16. 2026-06-23 21:32 UTCEPSS rescore
  17. 2026-06-22 14:25 UTCEPSS rescore
  18. 2026-06-22 14:25 UTCEPSS rescore
  19. 2026-06-21 14:56 UTCEPSS rescore
  20. 2026-06-21 14:56 UTCEPSS rescore
  21. 2026-06-21 01:59 UTCEPSS rescore
  22. 2026-06-21 01:59 UTCEPSS rescore
  23. 2026-06-18 17:52 UTCEPSS rescore
  24. 2026-06-16 17:52 UTCEPSS rescore
  25. 2026-06-15 17:48 UTCEPSS rescore
  26. 2026-06-14 23:18 UTCEPSS rescore
  27. 2026-06-13 23:00 UTCEPSS rescore
  28. 2026-06-13 23:00 UTCEPSS rescore
  29. 2026-06-12 23:12 UTCEPSS rescore
  30. 2026-06-12 03:32 UTCVendor advisory
  31. 2026-06-12 03:32 UTCGHSA enrichment
  32. 2026-06-11 14:00 UTCEPSS rescore
  33. 2026-06-10 22:18 UTCEPSS rescore
  34. 2026-06-10 21:47 UTCVendor advisory
  35. 2026-06-10 21:47 UTCGHSA enrichment
  36. 2026-06-10 13:22 UTCEPSS rescore
  37. 2026-06-09 19:44 UTCVendor advisory
  38. 2026-06-09 19:44 UTCGHSA enrichment
  39. 2026-06-08 14:17 UTCEPSS rescore
  40. 2026-06-08 14:17 UTCEPSS rescore
  41. 2026-06-07 17:53 UTCVendor advisory
  42. 2026-06-07 17:53 UTCGHSA enrichment
  43. 2026-06-07 15:25 UTCEPSS rescore
  44. 2026-06-07 15:24 UTCEPSS rescore
  45. 2026-06-06 13:47 UTCEPSS rescore
  46. 2026-06-06 13:47 UTCEPSS rescore
  47. 2026-06-06 13:47 UTCEPSS rescore
  48. 2026-06-05 22:47 UTCEPSS rescore
  49. 2026-06-04 13:12 UTCEPSS rescore
  50. 2026-06-04 13:12 UTCEPSS rescore
  51. 2026-06-04 13:12 UTCEPSS rescore
  52. 2026-06-02 20:13 UTCEPSS rescore
  53. 2026-06-02 20:13 UTCEPSS rescore
  54. 2026-06-01 13:51 UTCEPSS rescore
  55. 2026-06-01 13:51 UTCEPSS rescore
  56. 2026-06-01 13:51 UTCEPSS rescore
  57. 2026-05-31 22:30 UTCEPSS rescore
  58. 2026-05-31 22:30 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-31 00:16 UTCEPSS rescore
  61. 2026-05-31 00:16 UTCEPSS rescore
  62. 2026-05-29 13:51 UTCEG score recompute
  63. 2026-05-29 13:51 UTCVendor advisory
  64. 2026-05-29 13:51 UTCGHSA enrichment
  65. 2026-05-29 13:44 UTCEPSS rescore
  66. 2026-05-29 13:44 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2026-23200?
CVE-2026-23200 is a medium vulnerability published on February 14, 2026. In the Linux kernel, the following vulnerability has been resolved: ipv6: Fix ECMP sibling count mismatch when clearing RTF_ADDRCONF syzbot reported a kernel BUG in fib6addrt2node() when adding an IPv6 route. [0] Commit f72514b3c569 ("ipv6: clear RA flags when adding a static route") introduced…
When was CVE-2026-23200 disclosed?
CVE-2026-23200 was first published in the National Vulnerability Database on February 14, 2026, with the most recent update on March 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-23200 actively exploited?
CVE-2026-23200 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-23200?
CVE-2026-23200 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-23200?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23200, 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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