VulnerabilityPublished 18 Oct 2026

CVE-2026-98801: Linux kernel · net: restrict SO_RESERVE_MEM to TCP sockets and cap max value

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in a467b05b201b5c26be52ed3081992fa9c0387648 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

Severity

High

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in a467b05b201b5c26be52ed3081992fa9c0387648, 5069ce898148bd799395c5a464e006cbb840f188, 492e04f9a00f3cc88a1f6899417b10f3019a624e +1

Exploitation evidence

Disclosed: evidence found.
CVE published 18 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 a467b05b201b5c26be52ed3081992fa9c0387648, 5069ce898148bd799395c5a464e006cbb840f188, 492e04f9a00f3cc88a1f6899417b10f3019a624e or 37e02c42a00be692c06343e11779aadc45f45971.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 2bb2f5fb21b0486ff69b7b4a1fe03a760527d133, < a467b05b201b5c26be52ed3081992fa9c0387648	Fixed in a467b05b201b5c26be52ed3081992fa9c0387648
LinuxLinux	Affected ≥ 2bb2f5fb21b0486ff69b7b4a1fe03a760527d133, < 5069ce898148bd799395c5a464e006cbb840f188	Fixed in 5069ce898148bd799395c5a464e006cbb840f188
LinuxLinux	Affected ≥ 2bb2f5fb21b0486ff69b7b4a1fe03a760527d133, < 492e04f9a00f3cc88a1f6899417b10f3019a624e	Fixed in 492e04f9a00f3cc88a1f6899417b10f3019a624e
LinuxLinux	Affected ≥ 2bb2f5fb21b0486ff69b7b4a1fe03a760527d133, < 37e02c42a00be692c06343e11779aadc45f45971	Fixed in 37e02c42a00be692c06343e11779aadc45f45971
LinuxLinux	Affected =5.16	Fixed in–

AI-suggested

A fix is available and has been applied in specific Linux kernel commits. The patch restricts SO_RESERVE_MEM usage to TCP sockets and caps the maximum allowed value to 1GB to prevent integer overflow. Users should update to a Linux kernel version that includes these fixes, identified by the provided commit hashes. No additional mitigation actions are indicated by the vendor advisory.

Description

A vulnerability in the Linux kernel related to the SO_RESERVE_MEM socket option has been resolved. The issue involved improper handling of SO_RESERVE_MEM on UDP sockets, which are only supported for TCP sockets. This could lead to memory accounting corruption due to concurrent access and lack of proper locking. Additionally, there was no upper bound on the SO_RESERVE_MEM value, allowing values near INT_MAX to cause integer overflows and memory corruption. The fix restricts SO_RESERVE_MEM usage to TCP sockets and caps the maximum value to 1GB.

Impact

The vulnerability could lead to memory accounting corruption in the Linux kernel networking stack when SO_RESERVE_MEM is used on UDP sockets, which are not properly supported. This can cause data structure corruption related to socket memory reservation and memory control group accounting. The lack of an upper bound on the SO_RESERVE_MEM value could cause integer overflow, further corrupting memory accounting fields. These issues could potentially affect system stability or lead to denial of service conditions. There is no indication of known exploitation in the wild.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 09:56 UTC

Technical details

References

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