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TI-2026-46087 Aliases CVE-2026-64523GHSA-fc48-5g6g-x546

net/handshake: Take a long-lived file reference at submit

Priority MEDIUM 49CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 12 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: net/handshake: Take a long-lived file reference at submit handshake_nl_accept_doit() needs the file pointer backing req->hr_sk->sk_socket to survive the window between handshake_req_next() and the subsequent FD_PREPARE() and get_file(). The submit-side sock_hold() does not provide that. sk_refcnt keeps struct sock alive, but struct socket is owned by sock->file: when the consumer fputs the last file reference, sock_release() tears the socket down regardless of any sock_hold. Add an hr_file pointer to struct handshake_req and acquire an explicit reference on sock->file during handshake_req_submit(). handshake_complete() and handshake_req_cancel() release the reference on the completion-bit-winning path. The submit error path must also release the file reference, but after rhashtable insertion a concurrent handshake_req_cancel() can discover the request and race the error path. Gate the error-path cleanup -- sk_destruct restoration, fput, and request destruction -- with test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED), the same serialization handshake_complete() and handshake_req_cancel() already use. When cancel has already claimed ownership, the submit error path returns without touching the request; socket teardown handles final destruction. The accept-side dereferences are not yet retargeted; that change comes in the next patch.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0045 39th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.6.160, 6.12.93, 6.18.44 +2Red Hat: 2 advisoriesRed Hat: 12 fixed, 1 without a fix

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 later6.6.160, 6.12.93, 6.18.44, 7.0.12, 7.1Patch availableCNA
  • Linux VendorLinux Affected 6.4 and later Fixed in 6.6.160, 6.12.93, 6.18.44, 7.0.12, 7.1 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 6.6.160, 6.12.93, 6.18.44, 7.0.12, 7.1

Red Hat 2 advisories

  • RHSA-2026:91565 Released 2026-10-28 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • 10Base-SMTV kernel-modules-internal-6.12.0-211.69.1.el10_2
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.69.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.69.1.el10_2, kernel-64k-devel-6.12.0-211.69.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.69.1.el10_2, kernel-64k-6.12.0-211.69.1.el10_2, kernel-64k-core-6.12.0-211.69.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.69.1.el10_2, libperf-6.12.0-211.69.1.el10_2
    • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.69.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.69.1.el10_2, kernel-rt-64k-6.12.0-211.69.1.el10_2, kernel-rt-64k-core-6.12.0-211.69.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.69.1.el10_2, kernel-rt-core-6.12.0-211.69.1.el10_2, kernel-rt-debug-6.12.0-211.69.1.el10_2 +9
  • RHSA-2026:90365 Released 2026-10-26 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.61.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.61.1.el9_8, kernel-64k-devel-5.14.0-687.61.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.61.1.el9_8, kernel-64k-5.14.0-687.61.1.el9_8, kernel-64k-core-5.14.0-687.61.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.61.1.el9_8, libperf-5.14.0-687.61.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.61.1.el9_8, kernel-rt-64k-5.14.0-687.61.1.el9_8, kernel-rt-64k-core-5.14.0-687.61.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.61.1.el9_8, kernel-rt-core-5.14.0-687.61.1.el9_8, kernel-rt-debug-5.14.0-687.61.1.el9_8 +9

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 9AffectedNo fix yet
10Base-SMTVFixed RHSA-2026:91565
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:91565
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:90365
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:91565
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:90365
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:91565
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:90365
Red Hat Enterprise Linux Hidden (v. 10)Fixed RHSA-2026:91565
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:91565
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:90365
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:91565
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:90365
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-64523
  2. 2026-10-03 Alias added: GHSA-fc48-5g6g-x546
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-20 Weakness changed · CISA ADP
  5. 2026-10-21 Fix available: Linux/Linux@22e371a93563c30ebebc576db049785e0d7fc617, Linux/[email protected] · CNA
  6. 2026-10-21 1 new reference · CNA
  7. 2026-10-27 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) +2 · Red Hat
  8. 2026-10-28 EPSS moved to the below the 50th percentile
  9. 2026-10-29 Fix available: RHSA-2026:90365 · Red Hat
  10. 2026-10-29 Fix available: RHSA-2026:91565 · Red Hat
  11. 2026-10-30 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +4 · 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