Kernel data disclosure via speculative evdev indexing
Published Aug 22, 2026 · Updated Aug 25, 2026
Out-of-bounds read in Linux kernel evdev allows local users to disclose kernel data through crafted event-mask ioctls. The evdev_get_mask_cnt() bounds branch can be mistrained, so an unchecked 32-bit type speculatively indexes counts[] and client->evmasks[] before later copies create a timing channel. Access to an open /dev/input/eventN descriptor is required; the consequence is indirect kernel-memory disclosure rather than a committed out-of-bounds read.
Summary
What happened
Out-of-bounds read in Linux kernel evdev allows local users to disclose kernel data through crafted event-mask ioctls. The evdev_get_mask_cnt() bounds branch can be mistrained, so an unchecked 32-bit type speculatively indexes counts[] and client->evmasks[] before later copies create a timing channel. Access to an open /dev/input/eventN descriptor is required; the consequence is indirect kernel-memory disclosure rather than a committed out-of-bounds read.
The record
- CVE
- CVE-2026-74683
- Published
- Aug 22, 2026
- Updated
- Aug 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-125
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 22, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 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=06a16293f71927f756dcf37558a79c0b05a91641 <3abd29c61d2ef37c4102cf755b18be53bb9dbea6
- Affected versionversion=06a16293f71927f756dcf37558a79c0b05a91641 <4034ef247a9dde3f56660b01f0c3280dac6b1274
- Affected versionversion=06a16293f71927f756dcf37558a79c0b05a91641 <433913b4a92214d76e9f0c03ad9128fec943d5f8
- Affected versionversion=06a16293f71927f756dcf37558a79c0b05a91641 <5db341189bb7ff041d570dbe36ecca7e32913927
- Affected versionversion=06a16293f71927f756dcf37558a79c0b05a91641 <810e1883d4815f29c30d900ad7333d03cc2515d1
- Affected versionversion=06a16293f71927f756dcf37558a79c0b05a91641 <c79b08d8fa230871a3634e34a66e591ac2d084ef
- Affected versionversion=06a16293f71927f756dcf37558a79c0b05a91641 <f27fa9b39f925d26e034a1f382cb45523138f4ae
- Affected versionversion=06a16293f71927f756dcf37558a79c0b05a91641 <f3fc329acad9a71b3c077237cbac20670d2358c8
- Affected versionversion=4.4
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
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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