CVE-2026-98857 ipvs: bound LBLCR and LBLC cache growth
An attacker can cause a denial of service in the Linux kernel IPVS module by exhausting memory through unbounded cache growth in LBLCR and LBLC schedulers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98857?
CVE-2026-98857 is a denial of service vulnerability in Linux, published on 18 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ipvs: bound LBLCR and LBLC cache growth
ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for every previously unseen destination address. The table max_size only tells the periodic collector to reclaim entries after the cache has already exceeded the limit. It does not reclaim entries that the attacker continues to use.
Reject new cache entries once either table reaches max_size * 3 / 2. The extra headroom lets the periodic collector catch up while the existing scheduler fallback continues to use the selected destination when cache creation fails. New traffic therefore stays serviceable without growing the tables further.
Which versions are affected by CVE-2026-98857?
How do I fix CVE-2026-98857?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-98857 being exploited?
There is no known exploitation of CVE-2026-98857 in the wild and no public exploit code.
Sources
Also known as AZL-109176, BELL-CVE-2026-98857, DEBIAN-CVE-2026-98857, GHSA-3qgh-gjj6-qj8r, UBUNTU-CVE-2026-98857.