espintcp: remove encap socket caching to avoid reference leak
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 10 fixed, 2 without a fix
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: espintcp: remove encap socket caching to avoid reference leak The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.6 and later | 5.10.270, 5.15.221, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15 | Patch available | CNA |
- Linux VendorLinux Affected 5.6 and later Fixed in 5.10.270, 5.15.221, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15 Patch available CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.6 to before 6.1.141; 6.2 to before 6.6.93; 6.7 to before 6.12.31; 6.13 to before 6.14.9 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* | 6.15 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* | 6.15 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* | 6.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* | 6.15 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* | 6.15 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc6:*:*:*:*:*:* | 6.15 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc7:*:*:*:*:*:* | 6.15 rc7 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.6 to before 6.1.141; 6.2 to before 6.6.93; 6.7 to before 6.12.31; 6.13 to before 6.14.9 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* Versions 6.15 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* Versions 6.15 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* Versions 6.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* Versions 6.15 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* Versions 6.15 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc6:*:*:*:*:*:* Versions 6.15 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc7:*:*:*:*:*:* Versions 6.15 rc7 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.270, 5.15.221, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15
Red Hat 2 advisories
- RHSA-2026:18587 Released 2026-05-19 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.5.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.5.1.el9_8, kernel-64k-devel-5.14.0-687.5.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.5.1.el9_8, kernel-64k-5.14.0-687.5.1.el9_8, kernel-64k-core-5.14.0-687.5.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.5.1.el9_8, libperf-5.14.0-687.5.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.5.1.el9_8, kernel-rt-64k-5.14.0-687.5.1.el9_8, kernel-rt-64k-core-5.14.0-687.5.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.5.1.el9_8, kernel-rt-core-5.14.0-687.5.1.el9_8, kernel-rt-debug-5.14.0-687.5.1.el9_8 +9
- RHSA-2026:18134 Released 2026-05-19 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.7.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.7.1.el10_2, kernel-64k-devel-6.12.0-211.7.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.7.1.el10_2, kernel-64k-6.12.0-211.7.1.el10_2, kernel-64k-core-6.12.0-211.7.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.7.1.el10_2, libperf-6.12.0-211.7.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.7.1.el10_2, kernel-rt-64k-6.12.0-211.7.1.el10_2, kernel-rt-64k-core-6.12.0-211.7.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.7.1.el10_2, kernel-rt-core-6.12.0-211.7.1.el10_2, kernel-rt-debug-6.12.0-211.7.1.el10_2 +9
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:18134 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:18587 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:18134 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:18587 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:18134 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:18587 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:18134 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:18587 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:18134 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:18587 |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2025-38097
- 2026-10-03 Alias added: GHSA-jm67-vrwh-5hh6
- 2026-10-16 CISA SSVC decision points changed
References
Patch 5
- https://git.kernel.org/stable/c/e4cde54b46a87231c77256a633be1bef62687d69
- https://git.kernel.org/stable/c/b58a295d10065960bcb9d60cb8ca6ead9837cd27
- https://git.kernel.org/stable/c/9cbca30102028f9ad3d2098f935c4368f581fd07
- https://git.kernel.org/stable/c/74fd327767fb784c5875cf7c4ba1217f26020943
- https://git.kernel.org/stable/c/028363685bd0b7a19b4a820f82dd905b1dc83999
More Linux Kernel vulnerabilities
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- 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
Sources
- CVE-2025-38097 · CVE Program
- CVE-2025-38097 · NVD
- FIRST EPSS
- GHSA-jm67-vrwh-5hh6 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-38097 · Red Hat security data · CC BY 4.0
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