CVE-2026-98442: Linux kernel · net/sched: act_ct: fix helper UAF due to extensions realloc
Source GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in dad19b59da050cb60d3f7023dac2a042a84bf0bd : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in dad19b59da050cb60d3f7023dac2a042a84bf0bd, 8988f4d11f3fba0ab38122178836c683ad516a05, 1679bbf5fbeac52a310b1a58b2b301bbf388bdbf +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation 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.
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 has been implemented in the Linux kernel to address this use-after-free vulnerability by ensuring helpers are called only after all extensions are added. Users should apply the official kernel update containing this fix when available. No additional mitigation steps are indicated.
Description
A use-after-free (UAF) vulnerability in the Linux kernel's net/sched act_ct helper was resolved. The issue involved a raw pointer to the extensions area being stored in an expectations list, which could become invalid if extensions were reallocated before the helper was called. This could lead to accessing freed memory during expectation removal. The fix ensures helpers are called only after all extensions are added. The helper rejection behavior regarding marks and labels remains consistent with previous handling, and no atomicity guarantees are provided by the API.
References
- nvd.nist.gov/vuln/detail/CVE-2026-98442 (opens in a new tab)
- git.kernel.org/stable/c/1679bbf5fbeac52a310b1a58b2b301bbf388bdbf (opens in a new tab)
- git.kernel.org/stable/c/812c16a255e7773a544e88b39ae6daed25544d30 (opens in a new tab)
- git.kernel.org/stable/c/8988f4d11f3fba0ab38122178836c683ad516a05 (opens in a new tab)
- git.kernel.org/stable/c/dad19b59da050cb60d3f7023dac2a042a84bf0bd (opens in a new tab)