CVE-2026-98027: Linux kernel · net: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.0 High · fixed in cda5ac8fe8ac8e80b1703ebb8c4250726fc19739 : patch Linux kernel soon.
Data as of 26 Oct 2026, 15:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in cda5ac8fe8ac8e80b1703ebb8c4250726fc19739, c5b5c52b6524c9fb50def2260baac745c095ec3a, b1fffc273112e7284c5b705e186b43b5770cd3d5 +5
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation 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
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AI-suggested
This vulnerability has been fixed in multiple Linux kernel commits. Users and administrators should update affected Linux kernel installations to versions including these fixes. Since the vulnerability requires a specific kernel version (5.4) and is fixed in later commits, applying the official kernel patches or upgrading to a fixed kernel version is the recommended mitigation. No additional mitigations are indicated by the vendor advisory.
Description
CVE-2026-98027 is a high-severity vulnerability in the Linux kernel's mv88e6xxx driver related to the handling of policy rule dumps. The flaw allows a user to cause a buffer overrun by specifying fewer slots than existing rules when querying policy rules via ETHTOOL_GRXCLSRLALL, potentially leading to memory corruption. The issue arises because the function mv88e6xxx_get_rxnfc() overwrites the caller's input buffer size before it is checked, resulting in out-of-bounds memory access. This vulnerability affects Linux kernel version 5.4 and has been fixed in several subsequent commits.
References
- git.kernel.org/stable/c/7e4bfc5f0b66feb22cba821303fc25ca22cd0887 (opens in a new tab)
- git.kernel.org/stable/c/01124cd2cf4b71755b1130ac82d78dcfbd5d69e3 (opens in a new tab)
- git.kernel.org/stable/c/609c4378f212cf580aae02250f1146caf63d873f (opens in a new tab)
- git.kernel.org/stable/c/c5b5c52b6524c9fb50def2260baac745c095ec3a (opens in a new tab)
- git.kernel.org/stable/c/44cd4674d9aa5bdf793b8a8b481c9e8536ed6070 (opens in a new tab)
- git.kernel.org/stable/c/7a683c2b062810bca203e41866389daf387c235b (opens in a new tab)
- git.kernel.org/stable/c/cda5ac8fe8ac8e80b1703ebb8c4250726fc19739 (opens in a new tab)
- git.kernel.org/stable/c/b1fffc273112e7284c5b705e186b43b5770cd3d5 (opens in a new tab)