Pre-boot service interruption via regex buffer overwrite
Published Jan 27, 2026 · Updated Jan 27, 2026
Out-of-bounds write in CloverBootloader before 5162 allows local users to interrupt boot services through a crafted regular expression. The concat_opt_exact_str() function permits a multibyte character to fill the fixed optimization buffer exactly, then writes beyond its end while copying the character bytes. Exploitation requires local access to reach regular-expression compilation in the pre-boot environment and can corrupt memory, disrupting the bootloader and associated firmware service.
Summary
What happened
Out-of-bounds write in CloverBootloader before 5162 allows local users to interrupt boot services through a crafted regular expression. The concat_opt_exact_str() function permits a multibyte character to fill the fixed optimization buffer exactly, then writes beyond its end while copying the character bytes. Exploitation requires local access to reach regular-expression compilation in the pre-boot environment and can corrupt memory, disrupting the bootloader and associated firmware service.
The record
- CVE
- CVE-2026-24795
- Published
- Jan 27, 2026
- Updated
- Jan 27, 2026
- Vendor
- CloverHackyColor
- Product
- CloverBootloader
- Classifications
- CWE-787, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 27, 2026CVE publishedPublication date reported by the CVE source.
- Jan 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=0 <5162
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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Public exploit references
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Technologies
Your stack
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Your stack
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