CVE-2026-45905

MEDIUMNVD 4.74.7—
EchelonGraph scoreMEDIUM confidence

Score 4.7 from GitHub Security Advisory published 2026-05-27. NVD baseline CVSS 4.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
4.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.7Exploit: 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:

xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path

icmp_route_lookup() performs multiple route lookups to find a suitable route for sending ICMP error messages, with special handling for XFRM (IPsec) policies.

The lookup sequence is:

  • First, lookup output route for ICMP reply (dst = original src)
  • Pass through xfrm_lookup() for policy check
  • If blocked (-EPERM) or dst is not local, enter "reverse path"
  • In reverse path, call xfrm_decode_session_reverse() to get fl4_dec
which reverses the original packet's flow (saddr<->daddr swapped)
  • If fl4_dec.saddr is local (we are the original destination), use
__ip_route_output_key() for output route lookup
  • If fl4_dec.saddr is NOT local (we are a forwarding node), use
ip_route_input() to simulate the reverse packet's input path
  • Finally, pass rt2 through xfrm_lookup() with XFRM_LOOKUP_ICMP flag

The bug occurs in step 6: ip_route_input() is called with fl4_dec.daddr (original packet's source) as destination. If this address becomes local between the initial check and ip_route_input() call (e.g., due to concurrent "ip addr add"), ip_route_input() returns a LOCAL route with dst.output set to ip_rt_bug.

This route is then used for ICMP output, causing dst_output() to call ip_rt_bug(), triggering a WARN_ON:

------------[ cut here ]------------ WARNING: net/ipv4/route.c:1275 at ip_rt_bug+0x21/0x30, CPU#1 Call Trace: ip_push_pending_frames+0x202/0x240 icmp_push_reply+0x30d/0x430 __icmp_send+0x1149/0x24f0 ip_options_compile+0xa2/0xd0 ip_rcv_finish_core+0x829/0x1950 ip_rcv+0x2d7/0x420 __netif_receive_skb_one_core+0x185/0x1f0 netif_receive_skb+0x90/0x450 tun_get_user+0x3413/0x3fb0 tun_chr_write_iter+0xe4/0x220 ...

Fix this by checking rt2->rt_type after ip_route_input(). If it's RTN_LOCAL, the route cannot be used for output, so treat it as an error.

The reproducer requires kernel modification to widen the race window, making it unsuitable as a selftest. It is available at:

https://gist.github.com/mrpre/eae853b72ac6a750f5d45d64ddac1e81

CVSS v3
4.7
EG Score
4.7(medium)
EG Risk
26(Track)
EG Risk 26/100SSVC: 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
Severity47% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

May 27, 2026

Last Modified

June 24, 2026

Advisory Details (6)

Auto-updated Jun 24, 2026
No patch confirmed yet.
generic

xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b04061f89ffc6168e7ec3c71d0086ec3c3797228
generic

xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9a95ec9144eeff1fc6fbcc21b677e322c6f1430b
generic

xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/81b84de32bb27ae1ae2eb9acf0420e9d0d14bf00
generic

xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/423ce12d10b426709489d6b84fdaa6d2f31c5652
generic

xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2c1f59005da9dd4b07b26984fd719e36557dc57c
generic

xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1c9ef28f643cce34a6a6c36c8f4d6d60a60db7e1

Vendor Advisories for CVE-2026-45905(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 6.1.165—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.

Data Freshness Timeline

(refreshed 10× in last 7d / 31× 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. 2026-07-29 15:53 UTCEG score recompute
  2. 2026-07-29 15:53 UTCGHSA enrichment
  3. 2026-07-28 15:36 UTCEPSS rescore
  4. 2026-07-27 12:11 UTCEG score recompute
  5. 2026-07-27 12:11 UTCGHSA enrichment
  6. 2026-07-26 06:12 UTCOSV refresh
  7. 2026-07-25 14:18 UTCEPSS rescore
  8. 2026-07-24 14:17 UTCEPSS rescore
  9. 2026-07-23 14:18 UTCEPSS rescore
  10. 2026-07-23 03:16 UTCEG score recompute
  11. 2026-07-22 14:08 UTCEPSS rescore
  12. 2026-07-21 15:24 UTCEPSS rescore
  13. 2026-07-20 17:08 UTCEPSS rescore
  14. 2026-07-19 14:31 UTCEPSS rescore
  15. 2026-07-18 10:04 UTCEPSS rescore
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  17. 2026-07-15 16:57 UTCEPSS rescore
  18. 2026-07-13 22:30 UTCEPSS rescore
  19. 2026-07-13 06:13 UTCEPSS rescore
  20. 2026-07-11 08:27 UTCEPSS rescore
  21. 2026-07-09 19:10 UTCEPSS rescore
  22. 2026-07-09 00:24 UTCGHSA enrichment
  23. 2026-07-08 15:16 UTCEPSS rescore
  24. 2026-07-07 13:46 UTCEPSS rescore
  25. 2026-07-06 16:27 UTCEPSS rescore
Show 71 more
  1. 2026-07-06 02:23 UTCEPSS rescore
  2. 2026-07-05 02:30 UTCEPSS rescore
  3. 2026-07-04 06:31 UTCEPSS rescore
  4. 2026-07-01 15:07 UTCEPSS rescore
  5. 2026-07-01 11:36 UTCGHSA enrichment
  6. 2026-06-30 23:22 UTCEPSS rescore
  7. 2026-06-29 14:30 UTCGHSA enrichment
  8. 2026-06-28 14:07 UTCEPSS rescore
  9. 2026-06-28 07:27 UTCGHSA enrichment
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-28 04:56 UTCEPSS rescore
  12. 2026-06-27 06:34 UTCGHSA enrichment
  13. 2026-06-27 03:08 UTCEPSS rescore
  14. 2026-06-26 02:45 UTCGHSA enrichment
  15. 2026-06-25 13:49 UTCEPSS rescore
  16. 2026-06-25 01:44 UTCEG score recompute▲ 4.70
  17. 2026-06-25 01:44 UTCGHSA enrichment
  18. 2026-06-24 18:02 UTCNVD updateCVSS v3 → 4.7 · severity → MEDIUM
  19. 2026-06-24 14:05 UTCEPSS rescore
  20. 2026-06-23 21:33 UTCEPSS rescore
  21. 2026-06-23 21:33 UTCEPSS rescore
  22. 2026-06-22 14:25 UTCEPSS rescore
  23. 2026-06-22 14:25 UTCEPSS rescore
  24. 2026-06-21 14:56 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
  26. 2026-06-21 01:59 UTCEPSS rescore
  27. 2026-06-21 01:59 UTCEPSS rescore
  28. 2026-06-19 19:26 UTCEPSS rescore
  29. 2026-06-19 19:26 UTCEPSS rescore
  30. 2026-06-18 17:52 UTCEPSS rescore
  31. 2026-06-18 17:52 UTCEPSS rescore
  32. 2026-06-17 23:37 UTCGHSA enrichment
  33. 2026-06-17 17:53 UTCEPSS rescore
  34. 2026-06-16 17:52 UTCEPSS rescore
  35. 2026-06-15 17:49 UTCEPSS rescore
  36. 2026-06-15 03:42 UTCGHSA enrichment
  37. 2026-06-13 23:00 UTCEPSS rescore
  38. 2026-06-12 23:12 UTCEPSS rescore
  39. 2026-06-12 23:12 UTCEPSS rescore
  40. 2026-06-12 08:05 UTCGHSA enrichment
  41. 2026-06-11 14:00 UTCEPSS rescore
  42. 2026-06-10 22:18 UTCEPSS rescore
  43. 2026-06-10 13:22 UTCEPSS rescore
  44. 2026-06-10 13:22 UTCEPSS rescore
  45. 2026-06-09 12:29 UTCGHSA enrichment
  46. 2026-06-08 14:17 UTCEPSS rescore
  47. 2026-06-08 14:17 UTCEPSS rescore
  48. 2026-06-07 15:25 UTCEPSS rescore
  49. 2026-06-07 15:25 UTCEPSS rescore
  50. 2026-06-06 16:53 UTCGHSA enrichment
  51. 2026-06-06 13:47 UTCEPSS rescore
  52. 2026-06-06 13:47 UTCEPSS rescore
  53. 2026-06-05 22:47 UTCEPSS rescore
  54. 2026-06-05 06:10 UTCEPSS rescore
  55. 2026-06-05 06:10 UTCEPSS rescore
  56. 2026-06-04 13:12 UTCEPSS rescore
  57. 2026-06-04 13:12 UTCEPSS rescore
  58. 2026-06-03 21:17 UTCGHSA enrichment
  59. 2026-06-02 20:13 UTCEPSS rescore
  60. 2026-06-01 13:52 UTCEPSS rescore
  61. 2026-06-01 13:52 UTCEPSS rescore
  62. 2026-06-01 01:41 UTCGHSA enrichment
  63. 2026-05-31 22:30 UTCEPSS rescore
  64. 2026-05-31 22:30 UTCEPSS rescore
  65. 2026-05-31 00:16 UTCEPSS rescore
  66. 2026-05-31 00:16 UTCEPSS rescore
  67. 2026-05-29 13:44 UTCEPSS rescore
  68. 2026-05-29 13:44 UTCEPSS rescore
  69. 2026-05-28 13:44 UTCEPSS rescore
  70. 2026-05-28 13:44 UTCEPSS rescore
  71. 2026-05-27 14:17 UTCEG score recompute

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-45905?
CVE-2026-45905 is a medium vulnerability published on May 27, 2026. In the Linux kernel, the following vulnerability has been resolved: xfrm: fix iprtbug race in icmproutelookup reverse path icmproutelookup() performs multiple route lookups to find a suitable route for sending ICMP error messages, with special handling for XFRM (IPsec) policies. The lookup sequence…
When was CVE-2026-45905 disclosed?
CVE-2026-45905 was first published in the National Vulnerability Database on May 27, 2026, with the most recent update on June 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45905 actively exploited?
CVE-2026-45905 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 98.5% of all scored CVEs.
What is the CVSS score of CVE-2026-45905?
CVE-2026-45905 has a CVSS v3 base score of 4.7 (NVD).
How do I remediate CVE-2026-45905?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45905, 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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