CVE-2026-97984: Linux kernel · net: ipv6: Fix UDP length overflow with PMTU discover and big MTU
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in e01b7c176d9af2b7c22bb3fe12cf9a7904f99fdc : update Linux kernel when convenient.
Data as of 26 Oct 2026, 15:59 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in e01b7c176d9af2b7c22bb3fe12cf9a7904f99fdc, ce66352d3eb21825410af8b91db7cc4bb8e22c98, 1dd562f3019019ffdf4b396570613053facda9ee +2
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in specific Linux kernel commits referenced by their hashes. Users should update to a Linux kernel version that includes these fixes to remediate the vulnerability. No additional mitigation steps are indicated or required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's IPv6 implementation allows a UDP length overflow when Path MTU Discovery (PMTU) is enabled with large MTU settings. This occurs because the UDP length field can overflow its 16-bit limit when sending large packets over devices with an MTU larger than the IPv6 maximum MTU. The issue triggers a kernel warning and affects UDP sockets when IPV6_MTU_DISCOVER is set to IPV6_PMTUDISC_DO or IPV6_PMTUDISC_PROBE. The flaw has been fixed in specific Linux kernel commits.
References
- git.kernel.org/stable/c/1dd562f3019019ffdf4b396570613053facda9ee (opens in a new tab)
- git.kernel.org/stable/c/1d56a00ec91f2885c64ea5b8cea18cb746b91bbb (opens in a new tab)
- git.kernel.org/stable/c/ce66352d3eb21825410af8b91db7cc4bb8e22c98 (opens in a new tab)
- git.kernel.org/stable/c/e01b7c176d9af2b7c22bb3fe12cf9a7904f99fdc (opens in a new tab)
- git.kernel.org/stable/c/0ae10b6be49b425827659b23bcce498f80eb7182 (opens in a new tab)