VulnerabilityPublished 3 Nov 2025Updated 7 Nov 2025

CVE-2025-39702: Moderate · kernel security update

Affects Linux kernelSource GCVE Database

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Mentioned vulnerabilities

CVE-2025-39881

Not known to be exploited : upgrade to 6.12.0-55.42.1.el10_0 when convenient.

Data as of 4 Nov 2026, 18:43 UTC

Severity

Medium

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

Patch: Available – fixed in 6.12.0-55.42.1.el10_0

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Nov 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 4 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.

almalinux-10

What to do

Upgrade the AlmaLinux to 6.12.0-55.42.1.el10_0.

Patches and advisories

access.redhat.com/errata/RHSA-2025:19469 (opens in a new tab)

Affected software

Product	Affected	Fixed in
AlmaLinux 10kernel-abi-stablelists	Affected <6.12.0-55.42.1.el10_0	Fixed in 6.12.0-55.42.1.el10_0
AlmaLinux 10kernel-doc	Affected <6.12.0-55.42.1.el10_0	Fixed in 6.12.0-55.42.1.el10_0

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 is available and should be applied promptly. The fixed kernel version is 6.12.0-55.42.1.el10_0 or later. After applying the update, a system reboot is required for the fix to take effect. No additional mitigation steps are indicated by the vendor advisory.

Description

A moderate severity security update addresses a vulnerability in the Linux kernel's IPv6 segment routing MAC comparison, fixing it to be constant-time to prevent timing attacks (CVE-2025-39702). This update is part of a broader kernel security patch that also fixes a use-after-free issue in kernfs polling (CVE-2025-39881). The fix is included in Red Hat Enterprise Linux 10 kernel version 6.12.0-55.42.1.el10_0 and later. Systems must be rebooted after applying the update for the fix to take effect.

Impact

The vulnerability could allow an attacker to exploit timing differences in MAC address comparisons in IPv6 segment routing, potentially leaking sensitive information. The severity is rated Moderate by the vendor. There are no reports of active exploitation in the wild. The update also addresses a use-after-free vulnerability that could lead to system instability or potential privilege escalation if exploited.

References

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