VulnerabilityPublished 28 Oct 2026

CVE-2026-99211: Linux kernel · netlink: reset skb headers before unicast and multicast filtering

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 06791594274f87c29f1a9f1961d700272716a49d : update Linux kernel when convenient.

Data as of 28 Oct 2026, 10:58 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

Patch: Available – fixed in 06791594274f87c29f1a9f1961d700272716a49d, 06935da5de83aa8b98841563894857e7d2f80e47, 8bf659bd54e1f00e34cf5244b1d289c506fa47c0

Exploitation evidence

Disclosed: evidence found.
CVE published 28 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.

What to do

Upgrade Linux kernel to 06791594274f87c29f1a9f1961d700272716a49d, 06935da5de83aa8b98841563894857e7d2f80e47 or 8bf659bd54e1f00e34cf5244b1d289c506fa47c0.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ b1153f29ee07dc1a788964409255a4b4fae50b98, < 06791594274f87c29f1a9f1961d700272716a49d	Fixed in 06791594274f87c29f1a9f1961d700272716a49d
LinuxLinux	Affected ≥ b1153f29ee07dc1a788964409255a4b4fae50b98, < 06935da5de83aa8b98841563894857e7d2f80e47	Fixed in 06935da5de83aa8b98841563894857e7d2f80e47
LinuxLinux	Affected ≥ b1153f29ee07dc1a788964409255a4b4fae50b98, < 8bf659bd54e1f00e34cf5244b1d289c506fa47c0	Fixed in 8bf659bd54e1f00e34cf5244b1d289c506fa47c0
LinuxLinux	Affected =2.6.26	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =2.6.26	Fixed in–

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

Description

In the Linux kernel, the following vulnerability has been resolved: netlink: reset skb headers before unicast and multicast filtering Socket filters can use SKF_NET_OFF and SKF_LL_OFF to read relative to an skb's network and MAC headers. Netlink producers may reserve headroom without resetting those headers, allowing a receiving socket's filter to read data before the initialized message. For example, IWPM HELLO replies are allocated with dev_alloc_skb(), which reserves NET_SKB_PAD bytes. An unprivileged NETLINK_RDMA user can attach a classic socket filter and disclose this headroom through the length of the delivered reply. The resets in netlink_dump() do not help because IWPM sends a separately allocated skb through netlink_unicast(). Reset both headers before running the receiver's filter in unicast and broadcast delivery, as is already done for dump skbs. This also covers other netlink producers that reserve headroom without changing their allocation or message-building code.

References

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