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TI-2025-15943 Aliases CVE-2025-21993GHSA-ghxc-pm62-h5fx

iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()

Priority LOW 31CWE-125Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · High
Fix status
Partial Red Hat: 10 fixed, 3 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic() When performing an iSCSI boot using IPv6, iscsistart still reads the /sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix length is 64, this causes the shift exponent to become negative, triggering a UBSAN warning. As the concept of a subnet mask does not apply to IPv6, the value is set to ~0 to suppress the warning message.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00219 12th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.292, 5.10.236, 5.15.180 +5Red Hat: 2 advisoriesRed Hat: 10 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux2.6.26 and later5.4.292, 5.10.236, 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14Patch availableCNA
  • Linux VendorLinux Affected 2.6.26 and later Fixed in 5.4.292, 5.10.236, 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*before 6.1.132; 6.2 to before 6.6.84; 6.7 to before 6.12.20; 6.13 to before 6.13.8VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*6.14 rc1VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 6.1.132; 6.2 to before 6.6.84; 6.7 to before 6.12.20; 6.13 to before 6.13.8 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* Versions 6.14 rc1 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.4.292, 5.10.236, 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14

Red Hat 2 advisories

  • RHSA-2025:7956 Released 2025-05-19 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-55.12.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.12.1.el10_0, kernel-64k-devel-6.12.0-55.12.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-55.12.1.el10_0, kernel-64k-6.12.0-55.12.1.el10_0, kernel-64k-core-6.12.0-55.12.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-55.12.1.el10_0, libperf-6.12.0-55.12.1.el10_0
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-55.12.1.el10_0, kernel-rt-64k-6.12.0-55.12.1.el10_0, kernel-rt-64k-core-6.12.0-55.12.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-55.12.1.el10_0, kernel-rt-core-6.12.0-55.12.1.el10_0, kernel-rt-debug-6.12.0-55.12.1.el10_0 +11
  • RHSA-2025:7423 Released 2025-05-13 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-570.16.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.16.1.el9_6, kernel-64k-devel-5.14.0-570.16.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-570.16.1.el9_6, kernel-64k-5.14.0-570.16.1.el9_6, kernel-64k-core-5.14.0-570.16.1.el9_6 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-570.16.1.el9_6, libperf-5.14.0-570.16.1.el9_6
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-570.16.1.el9_6, kernel-rt-64k-5.14.0-570.16.1.el9_6, kernel-rt-64k-core-5.14.0-570.16.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-570.16.1.el9_6, kernel-rt-core-5.14.0-570.16.1.el9_6, kernel-rt-debug-5.14.0-570.16.1.el9_6 +11

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2025:7956
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2025:7423
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2025:7956
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2025:7423
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2025:7956
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2025:7423
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2025:7956
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2025:7423
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2025:7956
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2025:7423

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-21993
  2. 2026-10-03 Alias added: GHSA-ghxc-pm62-h5fx
  3. 2026-10-29 Affected versions changed · Red Hat

References

Patch 8

  • 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-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
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

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