CVE-2026-98487: Linux kernel · net: bridge: mdb: restart port group walk after deletion
Source GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in fe2a42789c12eb7c5d3a42191e2cc735a6c35ead : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in fe2a42789c12eb7c5d3a42191e2cc735a6c35ead, ab1404ac81154a89fb61ac50ae9a04cd8d4834dc, ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe +1
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 Linux kernel to fe2a42789c12eb7c5d3a42191e2cc735a6c35ead, ab1404ac81154a89fb61ac50ae9a04cd8d4834dc, ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe or 46ec55855c972504258c371677ac039ba20e5d12.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
|
| 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 that resets the cursor after each deletion to prevent stale pointer dereferences. Since the vulnerability is resolved in the Linux kernel, users should apply the official kernel updates containing this fix. No additional mitigation steps are indicated.
Description
A use-after-free vulnerability in the Linux kernel's network bridge multicast database (MDB) handling was resolved. The issue occurs when the br_mdb_flush_pgs() function walks through port groups and a deletion causes the cursor to point to freed memory, leading to a stale pointer dereference. This can be triggered by an RTM_GETMDB operation, resulting in a kernel slab-use-after-free error detected by KASAN.
References
- nvd.nist.gov/vuln/detail/CVE-2026-98487 (opens in a new tab)
- git.kernel.org/stable/c/46ec55855c972504258c371677ac039ba20e5d12 (opens in a new tab)
- git.kernel.org/stable/c/ab1404ac81154a89fb61ac50ae9a04cd8d4834dc (opens in a new tab)
- git.kernel.org/stable/c/ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe (opens in a new tab)
- git.kernel.org/stable/c/fe2a42789c12eb7c5d3a42191e2cc735a6c35ead (opens in a new tab)