VulnerabilityPublished 13 Nov 2026

CVE-2025-21656: linux-fips vulnerabilities

Affects Linux kernelSource GCVE Database

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Authoritative record:CVE-2025-21656· Low

Not known to be exploited : upgrade to 5.15.0-203.213+fips1 when convenient.

Data as of 13 Nov 2026, 21:18 UTC

Severity

Low

Rated Low by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in 5.15.0-203.213+fips1

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Jan 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 13 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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-9027-2

What to do

Upgrade the Ubuntu linux-fips package to 5.15.0-203.213+fips1.

Patches and advisories

ubuntu.com/security/notices/USN-9027-2 (opens in a new tab)

Affected software

Product	Affected	Fixed in
Ubuntu Pro FIPS-updates 22.04 LTSlinux-fips`pkg:deb/ubuntu/linux-fips?arch=source&distro=fips-updates/jammy`Other threats	Affected <5.15.0-203.213+fips1	Fixed in 5.15.0-203.213+fips1

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-fips version 5.15.0-203.213+fips1. Users should apply the update via their standard system update process and reboot the system to activate the fixes. Due to an ABI change in the kernel update, all third-party kernel modules must be recompiled and reinstalled. If standard kernel metapackages are installed, this process is handled automatically during the upgrade.

Description

Multiple security vulnerabilities were discovered in the Linux kernel (linux-fips), affecting several subsystems including x86 architecture, hardware monitoring drivers, OCFS2 file system, IPv4 networking, Ethernet bridge, Netfilter, and XFRM subsystem. These vulnerabilities could potentially allow an attacker to compromise the system. A security update correcting these flaws is available and requires a system reboot and recompilation of third-party kernel modules due to ABI changes.

References

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