Kernel use-after-free via stale pipefs superblock pointer
Published Sep 11, 2026 · Updated Sep 11, 2026
Use-after-free in Linux kernel sunrpc pipefs handling allows attackers to access stale kernel client state after a remount. The mount-event path calls rpc_setup_pipedir_sb without refreshing clnt->pipefs_sb, while unmount removes the directory without clearing that pointer. Exploitation requires a late pipefs mount or remount followed by rpc_info_open or rpc_show_info access; the source does not specify the resulting impact.
Summary
What happened
Use-after-free in Linux kernel sunrpc pipefs handling allows attackers to access stale kernel client state after a remount. The mount-event path calls rpc_setup_pipedir_sb without refreshing clnt->pipefs_sb, while unmount removes the directory without clearing that pointer. Exploitation requires a late pipefs mount or remount followed by rpc_info_open or rpc_show_info access; the source does not specify the resulting impact.
The record
- CVE
- CVE-2026-89543
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 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=17866066b8ac1cc38fb449670bc15dc9fee4b40a
- Affected versionversion=194454afa6aa9d6ed74f0c57127bc8beb27c20df
- Affected versionversion=1cdb52ffd6600a37bd355d8dce58ecd03e55e618
- Affected versionversion=4.19.318 <4.20
- Affected versionversion=5.10.202 <5.11
- Affected versionversion=5.15.140 <5.16
- Affected versionversion=5.4.280 <5.5
- Affected versionversion=6.1.64 <6.2
- Affected versionversion=6.5.13 <6.6
- Affected versionversion=6.6.3 <6.7
- Affected versionversion=6.7
- Affected versionversion=7749fd2dbef72a52b5c9ffdbf877691950ed4680
- Affected versionversion=7d61d1da2ed1f682c41cae0c8d4719cdaccee5c5
- Affected versionversion=bfca5fb4e97c46503ddfc582335917b0cc228264 <932a8cf6abb2b2f8677b79153a823108d8861fe2
- Affected versionversion=bfca5fb4e97c46503ddfc582335917b0cc228264 <cdf7a233cb94774b0e7df42d9157077983f5022c
- Affected versionversion=bfca5fb4e97c46503ddfc582335917b0cc228264 <e769fcde3cc73e847b1eb3acd40c04a291cb0c0c
- Affected versionversion=cc2e7ebbeb1d0601f7f3c8d93b78fcc03a95e44a
- Affected versionversion=dedf2a0eb9448ae73b270743e6ea9b108189df46
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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