CVE-2026-99071
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AI Threat Summary
CVE-2026-99071 is a moderate vulnerability affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv4: do not warn on route notification size race Commit 680aea08e78c ("net: ipv4: Emit notification when fib hardware flags are changed") added asynchronous route notifications for hardware flag changes. fib_alias_hw_flags_set() sizes the skb with fib_nlmsg_size() and later fills it with fib_dump_info() while holding only RCU. With nexthop compatibility mode enabled, a concurrent replacement can grow the group between these independent snapshots. fib_dump_info() can then legitimately return -EMSGSIZE, so the warning does not prove a sizing bug. Remove the warning. The existing error path still frees the skb and reports the error to listeners.
Attack Chain
Attacker scans for vulnerable versions using version banners or PoC scanners
Attacker triggers CVE-2026-99071 vulnerability with a crafted request or payload
Vulnerability exploited to perform unauthorized actions on the target system
Depending on vulnerability type, attacker achieves data access, service disruption, or code execution
MITRE ATT&CK Techniques
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-99071 |
| CVSS Score | N/A |
| Published | 2026-10-23 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |
References
- https://git.kernel.org/stable/c/088ba80eef85fa7a5ad8f9e7c82b…
- https://git.kernel.org/stable/c/221ef5e1e44a044790f0f54e6aa2…
- https://git.kernel.org/stable/c/78a1cf5c54b2f795c81fedb53075…
- https://git.kernel.org/stable/c/7dfa7ca97f3ac46353edd4cc44f7…
- https://git.kernel.org/stable/c/e02a5b6588161673ef75a4bc5cdf…