CVE-2026-72330 net/tls: Consume empty data records in tls_sw_read_sock()

Q: Is CVE-2026-72330 being exploited?

There is no known exploitation of CVE-2026-72330 in the wild and no public exploit code.

High 7.5 Published 15 Aug 2026 Updated 16 Oct 2026

A remote attacker can cause a denial of service in the Linux kernel TLS implementation by sending zero-length records that block subsequent data processing.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-72330?

CVE-2026-72330 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 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:

net/tls: Consume empty data records in tls_sw_read_sock()

A peer may send a zero-length TLS application_data record; TLS 1.3 explicitly permits these as a traffic-analysis countermeasure (RFC 8446, Section 5.1). After decryption such a record has full_len == 0. tls_sw_read_sock() hands it to the read_actor, which has no payload to consume and returns zero. The loop treats a zero return as backpressure (used <= 0), requeues the skb at the head of rx_list, and stops. rx_list is serviced head-first on the next call, so the empty record is dequeued, fails the same way, and is requeued again; every later record on the connection is blocked behind it.

tls_sw_recvmsg() does not stall on this: a zero-length data record copies nothing and falls through to consume_skb(). Mirror that in the read_sock() path by recognizing an empty data record before the actor runs, consuming it, and continuing.

Which versions are affected by CVE-2026-72330?

How do I fix CVE-2026-72330?

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-2026-72330 being exploited?