In the Linux kernel, the following vulnerability has been resolved: ipv4: stop route notification sizing when nexthop group shrinks Commit… (CVE-2026-99072)
Description
A vulnerability in the Linux kernel related to IPv4 route notification sizing has been resolved. The issue involves improper handling of nexthop groups when they shrink, leading to a potential null pointer dereference in fib_nexthop_nlmsg_size(). This occurs because the code does not stop sizing when an indexed path is absent after a nexthop group replacement with fewer paths. The fix prevents dereferencing a null pointer by stopping sizing in such cases.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in the Linux kernel's IPv4 routing code arises from a race condition between fib_nlmsg_size() and fib_info_nhc() when handling nexthop groups. Specifically, after a RTM_NEWNEXTHOP message replaces a nexthop group with fewer paths, fib_info_nhc() may return NULL while fib_nexthop_nlmsg_size() dereferences this null pointer, causing a potential kernel crash or instability. The patch stops the sizing operation when the indexed path is absent, preventing the null pointer dereference.
Potential Impact
The vulnerability can lead to a kernel null pointer dereference, which may cause a denial of service through kernel crash or instability. No information about privilege escalation or code execution is provided.
Mitigation Recommendations
A fix has been applied to the Linux kernel to address this issue. Users should update to the patched kernel version containing the fix. Since no vendor advisory or patch links are provided, check the official Linux kernel repositories or vendor advisories for the specific patch and update instructions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-wrfx-ch9c-5jj2
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-99072"]
Threat ID: 6adbaacbd73cc49347b204ec
Added to database: 10/23/2026, 18:43:23 UTC
Last enriched: 10/23/2026, 18:49:18 UTC
Last updated: 10/24/2026, 01:05:18 UTC
Views: 3
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.