CVE-2026-58084

Kernel stack disclosure via unchecked CLOCK_TAI failure

Published Aug 19, 2026 · Updated Aug 19, 2026

Information disclosure in ktimer in FreeBSD 15.0-RELEASE before p12 and 15.1-RELEASE before p2 allows local users to read kernel memory. When timer_settime(2) returns a previous timer value for a CLOCK_TAI timer, the kernel calls realtimer_gettime(), ignores its error when no TAI offset is configured, and copies an uninitialized output buffer to userspace. Exploitation requires local code execution and an unset TAI offset; the result is kernel stack disclosure rather than code execution, data modification, or a service interrupt.

CVSS severityUnavailable
Unscored
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in ktimer in FreeBSD 15.0-RELEASE before p12 and 15.1-RELEASE before p2 allows local users to read kernel memory. When timer_settime(2) returns a previous timer value for a CLOCK_TAI timer, the kernel calls realtimer_gettime(), ignores its error when no TAI offset is configured, and copies an uninitialized output buffer to userspace. Exploitation requires local code execution and an unset TAI offset; the result is kernel stack disclosure rather than code execution, data modification, or a service interrupt.

The record

CVE
CVE-2026-58084
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-908
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 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.

  1. Affected versionversion=15.0-RELEASE <p12
  2. Affected versionversion=15.1-RELEASE <p2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=15.0-RELEASE <p12; version=15.1-RELEASE <p2

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource

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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