Kernel crash via oversized reallocation copy
Published May 27, 2026 · Updated May 27, 2026
Memory corruption in Linux Kernel 6.18 through 6.18.26 and 6.19 through 7.0.3 allows local users to trigger a crash via a forced shrink. __do_krealloc() and kvrealloc() copy an old allocation or bucket size into a smaller destination instead of capping the copy at the new size. Exploitation requires low-privileged local access and an in-kernel caller that forces reallocation for new alignment or NUMA placement; the demonstrated result is an out-of-bounds kernel write and system crash.
Summary
What happened
Memory corruption in Linux Kernel 6.18 through 6.18.26 and 6.19 through 7.0.3 allows local users to trigger a crash via a forced shrink. __do_krealloc() and kvrealloc() copy an old allocation or bucket size into a smaller destination instead of capping the copy at the new size. Exploitation requires low-privileged local access and an in-kernel caller that forces reallocation for new alignment or NUMA placement; the demonstrated result is an out-of-bounds kernel write and system crash.
The record
- CVE
- CVE-2026-45990
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-190, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 27, 2026CVE publishedPublication date reported by the CVE source.
- May 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=2cd8231796b5e7133b1c3d66ad7d2a3c42c97258 <082a6d03a2d685a83a332666b500ad3966349588
- Affected versionversion=2cd8231796b5e7133b1c3d66ad7d2a3c42c97258 <38387ccc0fbe38d14fb4c2ad7ee1d7404e5e59fd
- Affected versionversion=2cd8231796b5e7133b1c3d66ad7d2a3c42c97258 <550fa6b5aabb096554536ac1e3ec96b76cbb35fd
- Affected versionversion=6.18
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- LKDTM KREALLOC_SHRINK_OVERFLOW reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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