CVE-2026-74752: Linux kernel · sctp: validate cookie AUTH state before use
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in 88619b117be1daf633ce32210570ce35a0bd1c98 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 13:07 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in 88619b117be1daf633ce32210570ce35a0bd1c98, 7f17984cfa697613800eb693e183b06884129bd3, 4a4410de8dc6903d859c9e1731fc6dcee28bd072 +1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 26 Aug 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 Linux kernel to 88619b117be1daf633ce32210570ce35a0bd1c98, 7f17984cfa697613800eb693e183b06884129bd3, 4a4410de8dc6903d859c9e1731fc6dcee28bd072 or 3dbb44d88b1e94dd31fe43588af7437b34b44d56.
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– |
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: validate cookie AUTH state before use When cookie authentication is disabled, COOKIE_ECHO restores fixed-size AUTH fields directly from peer-controlled cookie bytes. A forged RANDOM length, HMAC list, or CHUNKS list can then reach association consumers with lengths or identifiers that were never validated against the local backing arrays. A forged RANDOM length can cause out-of-bounds reads during key-vector construction. A forged HMAC identifier also caused a 32-byte write past a zero-length AUTH chunk, providing a primitive for a local privilege escalation chain. Validate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie trust boundary before copying them into the association. Reject invalid types, malformed lengths, unsupported HMAC identifiers, HMAC lists without SHA1, and forbidden chunk ids.
References
- git.kernel.org/stable/c/4a4410de8dc6903d859c9e1731fc6dcee28bd072 (opens in a new tab)
- git.kernel.org/stable/c/7f17984cfa697613800eb693e183b06884129bd3 (opens in a new tab)
- git.kernel.org/stable/c/88619b117be1daf633ce32210570ce35a0bd1c98 (opens in a new tab)
- git.kernel.org/stable/c/3dbb44d88b1e94dd31fe43588af7437b34b44d56 (opens in a new tab)