Remote teardown hangs via stale route rebinding
Published Dec 16, 2025 · Updated Dec 16, 2025
A route-cache race in affected Linux kernels allows remote attackers to leak route and device references through concurrent tunnel traffic. The find_exception and rt_bind_exception path can bind a new destination to an fnhe entry after fnhe_remove_oldest selects it for RCU deletion, leaving the destination reference permanently held. A reachable router must already forward broad IPv4 routes through a GRE or SIT tunnel; repeated triggering creates unbounded memory pressure, and one leak can hang device or network-namespace teardown.
Summary
What happened
A route-cache race in affected Linux kernels allows remote attackers to leak route and device references through concurrent tunnel traffic. The find_exception and rt_bind_exception path can bind a new destination to an fnhe entry after fnhe_remove_oldest selects it for RCU deletion, leaving the destination reference permanently held. A reachable router must already forward broad IPv4 routes through a GRE or SIT tunnel; repeated triggering creates unbounded memory pressure, and one leak can hang device or network-namespace teardown.
The record
- CVE
- CVE-2025-68241
- Published
- Dec 16, 2025
- Updated
- Dec 16, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 16, 2025CVE publishedPublication date reported by the CVE source.
- Dec 16, 2025Record 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=3e6bd2b583f18da9856fc9741ffa200a74a52cba
- Affected versionversion=4589a12dcf80af31137ef202be1ff4a321707a73
- Affected versionversion=5.15
- Affected versionversion=5867e20e1808acd0c832ddea2587e5ee49813874 <4b7210da22429765d19460d38c30eeca72656282
- Affected versionversion=5ae06218331f39ec45b5d039aa7cb3ddd4bb8008
- Affected versionversion=67d6d681e15b578c1725bad8ad079e05d1c48a8e <041ab9ca6e80d8f792bb69df28ebf1ef39c06af8
- Affected versionversion=67d6d681e15b578c1725bad8ad079e05d1c48a8e <0fd16ed6dc331636fb2a874c42d2f7d3156f7ff0
- Affected versionversion=67d6d681e15b578c1725bad8ad079e05d1c48a8e <298f1e0694ab4edb6092d66efed93c4554e6ced1
- Affected versionversion=67d6d681e15b578c1725bad8ad079e05d1c48a8e <ac1499fcd40fe06479e9b933347b837ccabc2a40
- Affected versionversion=67d6d681e15b578c1725bad8ad079e05d1c48a8e <b84f083f50ecc736a95091691339a1b363962f0e
- Affected versionversion=67d6d681e15b578c1725bad8ad079e05d1c48a8e <b8a44407bdaf2f0c5505cc7d9fc7d8da90cf9a94
- Affected versionversion=bed8941fbdb72a61f6348c4deb0db69c4de87aca
- Affected versionversion=e46e23c289f62ccd8e2230d9ce652072d777ff30 <69d35c12168f9c59b159ae566f77dfad9f96d7ca
- Affected versionversion=f10ce783bcc4d8ea454563a7d56ae781640e7dcb
- Affected versionversion=f484595be6b7ef9d095a32becabb5dae8204fb2a
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
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Technologies
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