CVE-2026-53218
Analyzed
Analyzed - Analysis Complete
Heap Out-of-Bounds Write in Linux Kernel Netfilter nft_exthdr
Vulnerability report for CVE-2026-53218, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-06-25
Last updated on: 2026-07-02
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | From 5.16 (inc) to 6.1.176 (exc) |
| linux | linux_kernel | From 6.2 (inc) to 6.6.143 (exc) |
| linux | linux_kernel | From 5.11 (inc) to 5.15.210 (exc) |
| linux | linux_kernel | From 6.13 (inc) to 6.18.36 (exc) |
| linux | linux_kernel | From 6.7 (inc) to 6.12.94 (exc) |
| linux | linux_kernel | From 6.19 (inc) to 7.0.13 (exc) |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | From 4.11 (inc) to 5.10.259 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-908 | The product uses or accesses a resource that has not been initialized. |
