Persistent interpreter write denial via removal imbalance
Published Aug 15, 2026 · Updated Aug 15, 2026
Denial of service in fs/binfmt_misc.c in Linux 4.8 and later unpatched kernels allows local users to leave an interpreter unwritable. put_binfmt_handler() closes an interpreter opened with MISC_FMT_OPEN_FILE without restoring write access, leaving i_writecount negative and later writes failing with ETXTBSY until inode eviction. Reachability requires local access to register and remove a binfmt_misc entry; the resulting interruption is limited to writes to the selected interpreter file.
Summary
What happened
Denial of service in fs/binfmt_misc.c in Linux 4.8 and later unpatched kernels allows local users to leave an interpreter unwritable. put_binfmt_handler() closes an interpreter opened with MISC_FMT_OPEN_FILE without restoring write access, leaving i_writecount negative and later writes failing with ETXTBSY until inode eviction. Reachability requires local access to register and remove a binfmt_misc entry; the resulting interruption is limited to writes to the selected interpreter file.
The record
- CVE
- CVE-2026-74487
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 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=4.8
- Affected versionversion=948b701a607f123df92ed29084413e5dd8cda2ed <3b522487a3a9162b1b519eefde7998d103e3e07b
- Affected versionversion=948b701a607f123df92ed29084413e5dd8cda2ed <db1856ea9196cf6e015d12199a34c0b9313c7bfa
- Affected versionversion=948b701a607f123df92ed29084413e5dd8cda2ed <fdc1d702bf3001586221fa07e598e876a0a854c5
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Attacks
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Technologies
Your stack
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