Kernel panic via PE hash-length underflow
Published Jul 27, 2026 · Updated Jul 27, 2026
Out-of-bounds read in Linux Kernel PE signature verification allows local users to panic the kernel through a crafted PE file. pefile_digest_pe_contents subtracts hashed_bytes plus certs_size from pelen without first checking that the addition fits or remains within the buffer, so the unsigned length underflows to about 4 GiB and crypto_shash_update reads past the allocation. The demonstrated kexec_file_load path requires high local privileges, and successful exploitation crashes the host without a reported data-disclosure or integrity impact.
Summary
What happened
Out-of-bounds read in Linux Kernel PE signature verification allows local users to panic the kernel through a crafted PE file. pefile_digest_pe_contents subtracts hashed_bytes plus certs_size from pelen without first checking that the addition fits or remains within the buffer, so the unsigned length underflows to about 4 GiB and crypto_shash_update reads past the allocation. The demonstrated kexec_file_load path requires high local privileges, and successful exploitation crashes the host without a reported data-disclosure or integrity impact.
The record
- CVE
- CVE-2026-64544
- Published
- Jul 27, 2026
- Updated
- Jul 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 27, 2026CVE publishedPublication date reported by the CVE source.
- Jul 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.17
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <627938383761fb4334b41ebe7ef438d6b8b19d60
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <6acd2fbd00f9c72aebefce63fc2e73e8f3d79061
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <7016377699b5b25b7ec3c0bf2ec3f983c7e95f7c
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <803591785d33cf13b6f73ce2796e8b9e6d5e6526
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <89efd998470a93284b7ad5a20d4e0e3c6858ae8e
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <b798ada5a5d1cb4cc4cfa72074b1b463eca6c506
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <e162bc386e71b5412425a38ee048e8d2185491b9
- Affected versionversion=af316fc442ef23901bbfcec5af55e69ca6ce9563 <f7dd32c5179d7755de18e21d5674b08f9e5cb180
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
No public exploit references are available in this record.
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
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo