Remote kernel disclosure or crash via strnlen overread
Published Aug 26, 2026 · Updated Aug 27, 2026
Out-of-bounds read in Linux 7.1 through 7.1.9 allows remote attackers to disclose kernel data or crash RISC-V systems via SMB. The ZBB-optimized arch/riscv/lib/strnlen.S loop loads the next machine word before checking the aligned count boundary, so a word begins at s + count. Exposure requires a RISC-V kernel with ZBB and a reachable kernel path such as pre-authentication ksmbd SMB1 negotiation; an unmapped following page causes an oops or panic.
Summary
What happened
Out-of-bounds read in Linux 7.1 through 7.1.9 allows remote attackers to disclose kernel data or crash RISC-V systems via SMB. The ZBB-optimized arch/riscv/lib/strnlen.S loop loads the next machine word before checking the aligned count boundary, so a word begins at s + count. Exposure requires a RISC-V kernel with ZBB and a reachable kernel path such as pre-authentication ksmbd SMB1 negotiation; an unmapped following page causes an oops or panic.
The record
- CVE
- CVE-2026-74751
- Published
- Aug 26, 2026
- Updated
- Aug 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-125, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 26, 2026CVE publishedPublication date reported by the CVE source.
- Aug 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5ba15d419fab848a3813eb56bbcad00e291fbc49 <5d588c684833e678a0008eb69c33190f01a65f4b
- Affected versionversion=5ba15d419fab848a3813eb56bbcad00e291fbc49 <e697e30f3dd2da3a1df7dc0980546d5b53aea4b6
- Affected versionversion=7.1
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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