Is there a public exploit for CVE-2026-99121?

No public exploit for CVE-2026-99121 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

— Unscored

In the Linux kernel, the following vulnerability has been resolved: ipv4: avoid divide by zero in fibrebalance fibrebalance() computes the…

CVE-2026-99121

In the Linux kernel, the following vulnerability has been resolved: ipv4: avoid divide by zero in fibrebalance fibrebalance() computes the total eligible nexthop weight in one pass and programs upper bounds in a second pass. A concurrent change to ignorerouteswithlinkdown can make the first pass return zero while the second pass sees an eligible nexthop, resulting in division by zero. If the first pass reports a zero total, set each nexthop upper bound to 1 and skip the division. This matches the IPv6 fix in commit d2c26c2911dd ("ipv6: avoid divide by zero in rt6multipathrebalance") and preserves the lock-free rebalance path.

Assessment

CVSS: Not yet scored
Severity: Unscored
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 28 October 2026
Last updated: 30 October 2026
Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

At the source

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