Local service interruption via forward-path assertion
Published May 27, 2026 · Updated May 27, 2026
Reachable assertion in the forwarding-path logic of Linux Kernel allows local users to interrupt service via a long path. The dev_fwd_path() helper increments the path count, then invokes WARN_ON_ONCE when the count reaches NET_DEVICE_PATH_STACK_MAX instead of only returning NULL. Userspace must construct a sufficiently long forward path, with IPIP tunnel support increasing reachability; a host panics only when kernel-warning panic behavior is enabled.
Summary
What happened
Reachable assertion in the forwarding-path logic of Linux Kernel allows local users to interrupt service via a long path. The dev_fwd_path() helper increments the path count, then invokes WARN_ON_ONCE when the count reaches NET_DEVICE_PATH_STACK_MAX instead of only returning NULL. Userspace must construct a sufficiently long forward path, with IPIP tunnel support increasing reachability; a host panics only when kernel-warning panic behavior is enabled.
The record
- CVE
- CVE-2026-45847
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-617, T1499.004
- 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?
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- Affected versionversion=5.13
- Affected versionversion=ddb94eafab8b597b05904c8277194ea2d6357fa9 <008e7a7c293b30bc43e4368dac6ea3808b75a572
- Affected versionversion=ddb94eafab8b597b05904c8277194ea2d6357fa9 <50422613185d505201167e8bdd2f2700790d5db6
- Affected versionversion=ddb94eafab8b597b05904c8277194ea2d6357fa9 <548244c2f542aa0ad49453e9306e715a3877bc44
- Affected versionversion=ddb94eafab8b597b05904c8277194ea2d6357fa9 <9464ca7a6e56ad1ebf48b2ad5c16871edfad10c6
- Affected versionversion=ddb94eafab8b597b05904c8277194ea2d6357fa9 <959ea349c7e2d4edf07b6838ca7e59345fe61a08
- Affected versionversion=ddb94eafab8b597b05904c8277194ea2d6357fa9 <a78d055ba7c31103ad02f8eceb0c452e154d2660
- Affected versionversion=ddb94eafab8b597b05904c8277194ea2d6357fa9 <dcf9b3c90e5560339649d088836529883fb509f3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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