net/tls: Consume empty data records in tls_sw_read_sock()
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-72330
- 2026-10-03 Alias added: GHSA-744x-88r4-xj59
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-16 Priority changed: LOW → MEDIUM
- 2026-10-29 Affected versions changed · Red Hat
- 2026-11-07 EPSS moved to the 50th–90th percentile
References
Other 5
- https://git.kernel.org/stable/c/0867b0f2513ebc1c475af9898c97f4772a68d964
- https://git.kernel.org/stable/c/c6b440cf766a557b08d25f1b571b3d57d039686e
- https://git.kernel.org/stable/c/e8a4c9fc437b16aef38f86ce3275677e36924259
- https://git.kernel.org/stable/c/ebc295ce343600c2d60c1e1e0c5d192080217457
- https://git.kernel.org/stable/c/3be28e2c9cd0230cb51fd4967df095273afd3848
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-72330 · CVE Program
- CVE-2026-72330 · NVD
- FIRST EPSS
- GHSA-744x-88r4-xj59 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-72330 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences