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TI-2026-50501 Aliases CVE-2026-72221GHSA-5gf3-c25p-fm95

sunrpc: wait for in-flight TLS handshake callback when cancel loses race

Priority MEDIUM 50Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

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: sunrpc: wait for in-flight TLS handshake callback when cancel loses race When wait_for_completion_interruptible_timeout() in svc_tcp_handshake() returns 0 (timeout) or -ERESTARTSYS (signal) and tls_handshake_cancel() then returns false, handshake_complete() has won the cancellation race: it has set HANDSHAKE_F_REQ_COMPLETED and is about to invoke svc_tcp_handshake_done(), but the callback's side effects on xpt_flags and on svsk->sk_handshake_done have not yet committed. The current code reads xpt_flags immediately to decide whether the session succeeded. Two races result. If the callback has executed set_bit(XPT_TLS_SESSION) but not yet clear_bit(XPT_HANDSHAKE), svc_tcp_handshake() sees a session, enqueues the transport, and returns. svc_xprt_received() then clears XPT_BUSY, a worker thread picks the transport up, the dispatcher in svc_handle_xprt() observes XPT_HANDSHAKE still set, and xpo_handshake is invoked a second time. That svc_tcp_handshake() calls init_completion(&svsk->sk_handshake_done) while the original callback concurrently calls complete_all() on it, corrupting the embedded swait_queue. If the callback has set HANDSHAKE_F_REQ_COMPLETED but not yet entered svc_tcp_handshake_done(), svc_tcp_handshake() reads XPT_TLS_SESSION as clear and tears the connection down even though the handshake is about to succeed. Wait for the callback to commit before inspecting xpt_flags. The completion is guaranteed to fire because handshake_complete() invokes svc_tcp_handshake_done() unconditionally once it has set HANDSHAKE_F_REQ_COMPLETED.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00635 50th percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.6.145, 6.12.97, 6.18.40 +2Red Hat: 2 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.4 and later6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2Patch availableCNA
  • Linux VendorLinux Affected 6.4 and later Fixed in 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2

Red Hat 2 advisories

  • RHSA-2026:95370 Released 2026-11-05 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.66.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.66.1.el9_8, kernel-64k-devel-5.14.0-687.66.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.66.1.el9_8, kernel-64k-5.14.0-687.66.1.el9_8, kernel-64k-core-5.14.0-687.66.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.66.1.el9_8, libperf-5.14.0-687.66.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.66.1.el9_8, kernel-rt-64k-5.14.0-687.66.1.el9_8, kernel-rt-64k-core-5.14.0-687.66.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.66.1.el9_8, kernel-rt-core-5.14.0-687.66.1.el9_8, kernel-rt-debug-5.14.0-687.66.1.el9_8 +9
  • RHSA-2026:95367 Released 2026-11-05 · Red Hat rating Important
    kernel security update
    • 10Base-SMTV kernel-modules-internal-6.12.0-211.74.1.el10_2
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.74.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.74.1.el10_2, kernel-64k-devel-6.12.0-211.74.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.74.1.el10_2, kernel-64k-6.12.0-211.74.1.el10_2, kernel-64k-core-6.12.0-211.74.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.74.1.el10_2, libperf-6.12.0-211.74.1.el10_2
    • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.74.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.74.1.el10_2, kernel-rt-64k-6.12.0-211.74.1.el10_2, kernel-rt-64k-core-6.12.0-211.74.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.74.1.el10_2, kernel-rt-core-6.12.0-211.74.1.el10_2, kernel-rt-debug-6.12.0-211.74.1.el10_2 +9

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
10Base-SMTVFixed RHSA-2026:95367
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:95367
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:95367
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:95367
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux Hidden (v. 10)Fixed RHSA-2026:95367
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:95367
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:95367
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:95370
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

  1. 2026-10-02 Threatist record created from CVE-2026-72221
  2. 2026-10-03 Alias added: GHSA-5gf3-c25p-fm95
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-16 CVSS score changed · Red Hat
  5. 2026-10-16 CISA SSVC decision points changed
  6. 2026-10-25 EPSS moved to the 50th–90th percentile
  7. 2026-10-29 Affected versions changed · Red Hat
  8. 2026-11-05 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9) +9 · Red Hat
  9. 2026-11-06 Fix available: RHSA-2026:95370 · Red Hat
  10. 2026-11-06 Fix available: RHSA-2026:95367 · Red Hat

References

Other 5

  • 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
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences