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CVE-2026-72330

HIGHCVSS 7.5/10EPSS 0.21%

Last modified

CVE-2026-72330 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.21%

11.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 662fbcec32f4af6bdcf5b4006b792ebe9543d945, < 0867b0f2513ebc1c475af9898c97f4772a68d964; >= 662fbcec32f4af6bdcf5b4006b792ebe9543d945, < c6b440cf766a557b08d25f1b571b3d57d039686e; >= 662fbcec32f4af6bdcf5b4006b792ebe9543d945, < e8a4c9fc437b16aef38f86ce3275677e36924259; >= 662fbcec32f4af6bdcf5b4006b792ebe9543d945, < ebc295ce343600c2d60c1e1e0c5d192080217457; >= 662fbcec32f4af6bdcf5b4006b792ebe9543d945, < 3be28e2c9cd0230cb51fd4967df095273afd3848
LinuxLinux6.6

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-72330?
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.
How severe is CVE-2026-72330?
CVE-2026-72330 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-72330?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST