VulnerabilityPublished 26 Oct 2026

CVE-2026-99088: Linux kernel · net: openvswitch: validate transport header presence in set_ipv6_addr

Source GCVE Database

Authoritative record:CVE-2026-99088· Low

Not known to be exploited · fixed in b7b80d204abdc258006f9e17c92b363ab13bb599 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 16:35 UTC

Severity

Low

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

Patch: Available – fixed in b7b80d204abdc258006f9e17c92b363ab13bb599, 2594795fd832f0253826d64ff8976b8ff5fbfe9f, 6774af7cd17be8f0d0f70de3a749d381b4f2e9da +2

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Oct 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.

ghsa-hwf6-223w-r64q

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b, < b7b80d204abdc258006f9e17c92b363ab13bb599	Fixed in b7b80d204abdc258006f9e17c92b363ab13bb599
LinuxLinux	Affected ≥ 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b, < 2594795fd832f0253826d64ff8976b8ff5fbfe9f	Fixed in 2594795fd832f0253826d64ff8976b8ff5fbfe9f
LinuxLinux	Affected ≥ 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b, < 6774af7cd17be8f0d0f70de3a749d381b4f2e9da	Fixed in 6774af7cd17be8f0d0f70de3a749d381b4f2e9da
LinuxLinux	Affected ≥ 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b, < 6b8897ba0733f88f0360ea48a970f373f9142de0	Fixed in 6b8897ba0733f88f0360ea48a970f373f9142de0
LinuxLinux	Affected ≥ 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b, < 3c6a4b11330fe424557538a98fca9f0a4c5bf313	Fixed in 3c6a4b11330fe424557538a98fca9f0a4c5bf313
LinuxLinux	Affected =3.8	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to address this issue by modifying update_ipv6_checksum() to return early when processing IPv6 fragments, avoiding uninitialized memory reads. Users should apply the official kernel updates that include this fix. No additional mitigation is required beyond applying the patch.

Description

A Linux kernel vulnerability in the Open vSwitch component related to IPv6 address rewriting on IPv6 fragments causes an uninitialized transport header to be accessed, triggering debug warnings under certain configurations. The issue arises because the transport header is not set for non-first IPv6 fragments, but the checksum update function reads the transport header unconditionally. The fix involves early return in the checksum update function to avoid reading uninitialized data for fragment packets.

References

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