VulnerabilityPublished 28 Jul 2026Updated 27 Oct 2026

CVE-2025-21709: linux-hwe-6.8 vulnerabilities

Affects Linux kernelSource GCVE Database

Mentioned vulnerabilities

Not known to be exploited : upgrade to 6.8.0-136.136~22.04.1 soon.

Data as of 28 Oct 2026, 05:11 UTC

Severity

High

Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.8.0-136.136~22.04.1

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

usn-8619-1

What to do

Upgrade the Ubuntu linux-hwe-6.8 package to 6.8.0-136.136~22.04.1.

Patches and advisories

ubuntu.com/security/notices/USN-8619-1 (opens in a new tab)

Affected software

Product	Affected	Fixed in
Ubuntu 22.04 LTSlinux-hwe-6.8`pkg:deb/ubuntu/linux-hwe-6.8?arch=source&distro=jammy`Other threats	Affected <6.8.0-136.136~22.04.1	Fixed in 6.8.0-136.136~22.04.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A security update fixing these vulnerabilities is available in linux-hwe-6.8 version 6.8.0-136.136~22.04.1. Users should apply this update promptly to mitigate the risks. Refer to the official Ubuntu security notice USN-8619-1 for detailed patch information and installation instructions.

Description

Multiple security vulnerabilities affecting the Linux kernel and certain AMD processors have been identified and addressed in the linux-hwe-6.8 update. These include speculative execution flaws in AMD processors that could expose sensitive data, privilege escalation risks due to improper isolation of shared resources, and entropy handling issues in RDSEED instructions. Additionally, numerous kernel subsystems and drivers across various architectures have been fixed to mitigate potential system compromise risks. A patch is available in version 6.8.0-136.136~22.04.1.

Impact

The vulnerabilities could allow local attackers to expose sensitive information via speculative execution side channels, escalate privileges by corrupting higher privilege instructions, and compromise the integrity and confidentiality of random values generated by RDSEED instructions. Additionally, the broad range of kernel subsystem flaws could be exploited to compromise system security. These issues collectively pose risks of information disclosure, privilege escalation, and system compromise.

References

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