netfilter: nft_exthdr: fix register tracking for F_PRESENT flag
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-908 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_exthdr: fix register tracking for F_PRESENT flag nft_exthdr_init() passes user-controlled priv->len to nft_parse_register_store(), which marks that many bytes in the register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT is set, the eval paths write only 1 byte (nft_reg_store8) or 4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4, registers beyond the first are never written, retaining uninitialized stack data from nft_regs. Bail out if userspace requests too much data when F_PRESENT is set.
Why it matters now
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.11 and later | 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 4.11 and later Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1 Patch available CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.11 to before 5.10.259; 5.11 to before 5.15.210; 5.16 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.94; 6.13 to before 6.18.36; 6.19 to before 7.0.13 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | 7.1 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | 7.1 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | 7.1 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | 7.1 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* | 7.1 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* | 7.1 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:* | 7.1 rc7 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.11 to before 5.10.259; 5.11 to before 5.15.210; 5.16 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.94; 6.13 to before 6.18.36; 6.19 to before 7.0.13 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* Versions 7.1 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* Versions 7.1 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:* Versions 7.1 rc7 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-53218
- 2026-10-03 Alias added: GHSA-3j78-pf43-6mvq
- 2026-11-06 CISA SSVC decision points changed
References
Patch 8
- https://git.kernel.org/stable/c/8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6
- https://git.kernel.org/stable/c/19748967d59c31d24d21d40b728570788310b237
- https://git.kernel.org/stable/c/46fc15a044e9938e7ea77786fb37edd2cd74f031
- https://git.kernel.org/stable/c/cd513e43b4b2bd1de39e2367bc4261c699a8652f
- https://git.kernel.org/stable/c/67b27434c43b68a97becda98c9f0c8cf6cba2134
- https://git.kernel.org/stable/c/78069a6d8bc86c9e036eb82c2af4a19cc1871a53
- https://git.kernel.org/stable/c/f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265
- https://git.kernel.org/stable/c/772cecf198da732faebb5dcfc46d66a505be8495
More Linux Kernel vulnerabilities
- 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
Sources
- CVE-2026-53218 · CVE Program
- CVE-2026-53218 · NVD
- FIRST EPSS
- GHSA-3j78-pf43-6mvq · GitHub Advisory Database · CC BY 4.0
- CVE-2026-53218 · Red Hat security data · CC BY 4.0
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