Service interruption via ICMP route race
Published May 27, 2026 · Updated May 27, 2026
Race condition in Linux Kernel 2.6.25 and later affected branches allows local users to trigger a kernel warning and interrupt service. In icmp_route_lookup(), a concurrent address change makes ip_route_input() return an RTN_LOCAL route whose output handler is ip_rt_bug(), but the code uses that route for ICMP output without rechecking its type. Exploitation requires low local privileges, an XFRM reverse-path lookup, and winning a narrow race that the published reproducer widens by modifying the kernel.
Summary
What happened
Race condition in Linux Kernel 2.6.25 and later affected branches allows local users to trigger a kernel warning and interrupt service. In icmp_route_lookup(), a concurrent address change makes ip_route_input() return an RTN_LOCAL route whose output handler is ip_rt_bug(), but the code uses that route for ICMP output without rechecking its type. Exploitation requires low local privileges, an XFRM reverse-path lookup, and winning a narrow race that the published reproducer widens by modifying the kernel.
The record
- CVE
- CVE-2026-45905
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-362, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 27, 2026CVE publishedPublication date reported by the CVE source.
- May 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.6.25
- Affected versionversion=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <1c9ef28f643cce34a6a6c36c8f4d6d60a60db7e1
- Affected versionversion=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <2c1f59005da9dd4b07b26984fd719e36557dc57c
- Affected versionversion=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <423ce12d10b426709489d6b84fdaa6d2f31c5652
- Affected versionversion=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <81b84de32bb27ae1ae2eb9acf0420e9d0d14bf00
- Affected versionversion=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <9a95ec9144eeff1fc6fbcc21b677e322c6f1430b
- Affected versionversion=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <b04061f89ffc6168e7ec3c71d0086ec3c3797228
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- ip_rt_bug race condition reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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