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TI-2026-45862 Aliases CVE-2026-64298GHSA-mj8v-3x8m-9rx7

NFSv4: include MAY_WRITE in open permission mask for O_TRUNC

Priority LOW 30CWE-862Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · High
Fix status
Partial Red Hat: 14 fixed, 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-862.

Summary

In the Linux kernel, the following vulnerability has been resolved: NFSv4: include MAY_WRITE in open permission mask for O_TRUNC POSIX requires write permission to truncate a file, so an open() that specifies O_TRUNC must be authorized for write access regardless of the O_ACCMODE access mode. nfs_open_permission_mask() builds the access mask passed to nfs_may_open(), which is the local authorization gate for OPENs the client serves itself from a cached write delegation via the can_open_delegated() path in nfs4_try_open_cached(). The mask is derived from O_ACCMODE alone, so an open(O_RDONLY | O_TRUNC) against a file the caller cannot write requests only MAY_READ and passes the local check. The OPEN is then satisfied locally and the truncation is issued to the server as a SETATTR(size=0) over the delegation stateid, which the server accepts under standard write-delegation semantics. POSIX requires that this open fail with EACCES. Include MAY_WRITE in the mask whenever O_TRUNC is set so the local check matches the access the server would have enforced.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00147 3rd percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.261, 5.15.212, 6.1.178 +5Red Hat: 4 advisoriesRed Hat: 14 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
LinuxLinux2.6.24 and later5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2Patch availableCNA
  • Linux VendorLinux Affected 2.6.24 and later Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*2.6.24 to before 5.10.261; 5.11 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*7.2 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*7.2 rc2VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.24 to before 5.10.261; 5.11 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:* Versions 7.2 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:* Versions 7.2 rc2 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2

Red Hat 4 advisories

  • RHSA-2026:63129 Released 2026-09-04 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.44.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.44.1.el9_8, kernel-64k-devel-5.14.0-687.44.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.44.1.el9_8, kernel-64k-5.14.0-687.44.1.el9_8, kernel-64k-core-5.14.0-687.44.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.44.1.el9_8, libperf-5.14.0-687.44.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.44.1.el9_8, kernel-rt-64k-5.14.0-687.44.1.el9_8, kernel-rt-64k-core-5.14.0-687.44.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.44.1.el9_8, kernel-rt-core-5.14.0-687.44.1.el9_8, kernel-rt-debug-5.14.0-687.44.1.el9_8 +9
  • RHSA-2026:63014 Released 2026-09-03 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.159.1.el8_10, kernel-4.18.0-553.159.1.el8_10, kernel-abi-stablelists-4.18.0-553.159.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.159.1.el8_10
  • RHSA-2026:63013 Released 2026-09-03 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-4.18.0-553.159.1.rt7.500.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-4.18.0-553.159.1.rt7.500.el8_10 +7
Show 1 more Red Hat advisories
  • RHSA-2026:61887 Released 2026-09-01 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.50.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.50.1.el10_2, kernel-64k-devel-6.12.0-211.50.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.50.1.el10_2, kernel-64k-6.12.0-211.50.1.el10_2, kernel-64k-core-6.12.0-211.50.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.50.1.el10_2, libperf-6.12.0-211.50.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.50.1.el10_2, kernel-rt-64k-6.12.0-211.50.1.el10_2, kernel-rt-64k-core-6.12.0-211.50.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.50.1.el10_2, kernel-rt-core-6.12.0-211.50.1.el10_2, kernel-rt-debug-6.12.0-211.50.1.el10_2 +9

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 yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:63014
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:63014
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:63013
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:63013
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:63129

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-64298
  2. 2026-10-03 Alias added: GHSA-mj8v-3x8m-9rx7
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-20 Weakness changed · CISA ADP

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