netfilter: bridge: make ebt_snat ARP rewrite writable
Summary
| CVE | CVE-2026-53266 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-25 09:16:44 UTC |
| Updated | 2026-09-19 04:17:53 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: make ebt_snat ARP rewrite writable The ebtables SNAT target keeps the Ethernet source address rewrite behind skb_ensure_writable(skb, 0). This is intentional: at the bridge ebtables hooks the Ethernet header is addressed through skb_mac_header()/eth_hdr(), while skb->data points at the Ethernet payload. Asking skb_ensure_writable() for ETH_HLEN bytes would check the payload, not the Ethernet header, and would reintroduce the small packet regression fixed by commit 63137bc5882a. However, the optional ARP sender hardware address rewrite is different. It writes through skb_store_bits() at an offset relative to skb->data: skb_store_bits(skb, sizeof(struct arphdr), info->mac, ETH_ALEN) skb_header_pointer() only safely reads the ARP header; it does not make the later sender hardware address range writable. If that range is still held in a nonlinear skb fragment backed by a splice-imported file page, skb_store_bits() maps the frag page and copies the new MAC address directly into it. Ensure the ARP SHA range is writable before reading the ARP header and before calling skb_store_bits(). |
Risk And Classification
Primary CVSS: v3.1 8.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS: 0.006450000 probability, percentile 0.490410000 (date 2026-10-01)
CISA KEV: Listed on 2026-09-18; due 2026-09-21; ransomware use Unknown
Problem Types: NVD-CWE-noinfo | CWE-787 | CWE-787 CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 8.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 8.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CISA Known Exploited Vulnerability
| Vendor | Linux |
|---|---|
| Product | Kernel |
| Name | Linux Kernel Out-of-Bounds Write Vulnerability |
| Required Action | Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. |
| Notes | This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: ; https://git.kernel.org/stable/c/bf84ad7c7a9ede46e31afaa41a1ba06a159e8c87; https://git.kernel.org/stable/c/76280b78cc9f23bdc6438e10ad6dff148ef8375b; https://git.kernel.org/stable/c/b7e91939ba9be805a62a257fa4e227dffbb88fa0; https://git.kernel.org/stable/c/afd64b59c3de9bbbdd3759e834fdc55cda716e0b; https://git.kernel.org/stable/c/153ea96c806aea395daba907a4f88480b6ad5093; https://git.kernel.org/stable/c/b18675263db1147c8e1cab625400c13a0d87bd2d; https://git.kernel.org/stable/c/c9b5ff59feffb92a147a84a5aa28acd2cb8ff4c5; https://git.kernel.org/stable/c/67ba971ae02514d85818fe0c32549ab4bfa3bf49 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-53266 |
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 bf84ad7c7a9ede46e31afaa41a1ba06a159e8c87 git | Not specified |
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 76280b78cc9f23bdc6438e10ad6dff148ef8375b git | Not specified |
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 b7e91939ba9be805a62a257fa4e227dffbb88fa0 git | Not specified |
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 afd64b59c3de9bbbdd3759e834fdc55cda716e0b git | Not specified |
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 153ea96c806aea395daba907a4f88480b6ad5093 git | Not specified |
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 b18675263db1147c8e1cab625400c13a0d87bd2d git | Not specified |
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 c9b5ff59feffb92a147a84a5aa28acd2cb8ff4c5 git | Not specified |
| CNA | Linux | Linux | affected 63137bc5882a1882c553d389fdeeeace86ee1741 67ba971ae02514d85818fe0c32549ab4bfa3bf49 git | Not specified |
| CNA | Linux | Linux | affected 2f3839075a5f8dcf116c1abe35b36b018ac62445 git | Not specified |
| CNA | Linux | Linux | affected 51ba2945a8ef65ae437c8f9ba05f0343aa82ae5b git | Not specified |
| CNA | Linux | Linux | affected b7d23c2c87584eb429f115c078ed511be8b18e29 git | Not specified |
| CNA | Linux | Linux | affected 5.4.73 5.5 semver | Not specified |
| CNA | Linux | Linux | affected 5.8.17 5.9 semver | Not specified |
| CNA | Linux | Linux | affected 5.9.2 5.10 semver | Not specified |
| CNA | Linux | Linux | affected 5.10 | Not specified |
| CNA | Linux | Linux | unaffected 5.10 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.259 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.210 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.176 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.143 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.94 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.36 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.13 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/b7e91939ba9be805a62a257fa4e227dffbb88fa0 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/153ea96c806aea395daba907a4f88480b6ad5093 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/76280b78cc9f23bdc6438e10ad6dff148ef8375b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/67ba971ae02514d85818fe0c32549ab4bfa3bf49 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| www.cisa.gov/known-exploited-vulnerabilities-catalog | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.cisa.gov | US Government Resource |
| git.kernel.org/stable/c/afd64b59c3de9bbbdd3759e834fdc55cda716e0b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/c9b5ff59feffb92a147a84a5aa28acd2cb8ff4c5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/b18675263db1147c8e1cab625400c13a0d87bd2d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/bf84ad7c7a9ede46e31afaa41a1ba06a159e8c87 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
| CISA Known Exploited Vulnerabilities catalog | CISA | www.cisa.gov | kev |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-09-18T00:00:00.000Z | CVE-2026-53266 added to CISA KEV |
There are currently no legacy QID mappings associated with this CVE.