CVE-2026-98123: Linux kernel · sctp: fix soft lockup from unpadded ASCONF-ACK parameter iteration
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.09% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| 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 has been implemented in the Linux kernel to reject malformed SCTP_PARAM_ERR_CAUSE parameters and synchronize parameter iteration padding rules, preventing the soft lockup and out-of-bounds read. Users should update affected Linux kernel versions to the fixed releases. No additional mitigations are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel SCTP implementation allows a remote attacker to cause a soft lockup (denial of service) by sending a crafted ASCONF-ACK parameter with unpadded or malformed length fields. This desynchronizes parameter iteration, causing an infinite loop in kernel softirq context. Additionally, an out-of-bounds read can occur due to insufficient length checks on SCTP_PARAM_ERR_CAUSE parameters. The issue affects specific Linux kernel versions and was discovered by Tencent Yunding Lab's ZeroHive.
References
- ubuntu.com/security/CVE-2026-98123 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98123 (opens in a new tab)
- git.kernel.org/stable/c/3be02999ab9131a4b96eb1eda4ca48b1cea80f03 (opens in a new tab)
- git.kernel.org/stable/c/2cb0b0b1ed69430bf73740377ea0a1c44c50db63 (opens in a new tab)
- git.kernel.org/stable/c/7ba84e2971d208a2d6413a334ec28a8a32cdce0f (opens in a new tab)
- git.kernel.org/stable/c/abf59d7f6fff23227256e8199aca5ade45758f8b (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-98123 (opens in a new tab)
- git.kernel.org/stable/c/4548d843e7b29f6d150d8caae4e64015fa226b0c (opens in a new tab)
- git.kernel.org/stable/c/5fbc6a778d5fce7628821236972596acb18e1065 (opens in a new tab)
- git.kernel.org/stable/c/7d8e7ab6a0665888beee91f7ad77ac805963c4fd (opens in a new tab)
- git.kernel.org/stable/c/ba54cad229977f4fae6355dbdaf117088414fdd0 (opens in a new tab)