Status: KEV | Advisory ID: CVE-2026-53266
| CVE | CVE-2026-53266 |
| CVSS | CVSS 8.8 (High): attack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is changed; confidentiality impact is high; integrity impact is high; availability impact is high. (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H) |
| Affected products | Linux Kernel |
| Exploitation status | Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation. |
| Classified as | CWE-787 (Out-of-bounds Write) |
| KEV listing | Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-09-18. |
| Federal remediation deadline | 2026-09-21 (CISA KEV, Binding Operational Directive). |
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().
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-53266 |