VulnerabilityPublished 28 Oct 2026

CVE-2026-99165: Linux kernel · sctp: revalidate output stream after association connect wait

Source GCVE Database

Authoritative record:CVE-2026-99165

Not known to be exploited · fixed in fd56ac95ec31a05b66e8938debfa847f49c0e993 : patch Linux kernel soon.

Data as of 28 Oct 2026, 13:47 UTC

Severity

High

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

Patch: Available – fixed in fd56ac95ec31a05b66e8938debfa847f49c0e993, b7ad72414c673ce1fa1f463e807cd4f34f8be9bf, 77a63d1b813b08c4e5a948f5e04fbaca6176aa8f

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.

ghsa-h9p5-q3g4-gm7m

What to do

Upgrade Linux kernel to fd56ac95ec31a05b66e8938debfa847f49c0e993, b7ad72414c673ce1fa1f463e807cd4f34f8be9bf or 77a63d1b813b08c4e5a948f5e04fbaca6176aa8f.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 668c9beb9020d5834ee9e43c208190a07d2b1928, < fd56ac95ec31a05b66e8938debfa847f49c0e993	Fixed in fd56ac95ec31a05b66e8938debfa847f49c0e993
LinuxLinux	Affected ≥ 668c9beb9020d5834ee9e43c208190a07d2b1928, < b7ad72414c673ce1fa1f463e807cd4f34f8be9bf	Fixed in b7ad72414c673ce1fa1f463e807cd4f34f8be9bf
LinuxLinux	Affected ≥ 668c9beb9020d5834ee9e43c208190a07d2b1928, < 77a63d1b813b08c4e5a948f5e04fbaca6176aa8f	Fixed in 77a63d1b813b08c4e5a948f5e04fbaca6176aa8f
LinuxLinux	Affected =4.16	Fixed in–
Debiandebian/linux`pkg:deb/debian/linux`Other threats	Affected =4.16	Fixed in–

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

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel by improving the validation logic of output streams after association connect wait. Users should apply the official kernel updates that include this fix.

Description

CVE-2026-99165 is a vulnerability in the Linux kernel SCTP implementation where improper validation of output streams after association connect wait can lead to a null pointer dereference. This occurs when message interleaving is enabled and the socket lock is dropped during association establishment, allowing handshake processing to reduce the output stream count and free extensions of removed streams. Subsequent send operations may dereference these freed extensions, causing kernel panic.

References

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