Linux · Kernel
CVE-2026-53266
netfilter: bridge: make ebt_snat ARP rewrite writable
Cos'è
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().
CISA: Linux Kernel contains an out-of-bounds write vulnerability in the ebtables SNAT target which allows an ARP sender hardware address rewrite to write directly into a nonlinear socket-buffer fragment backed by a splice-imported file page. The impacted product(s) could be end-of-life (EoL) and/or end-of-service (EoS). Users are advised to discontinue use and/or transition to a supported version.
Cosa fare
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.
Scadenza per le agenzie federali USA: 21 settembre 2026
- Aggiunta all'elenco CISA
- 18 settembre 2026
- Pubblicato
- 25 giugno 2026
- Gravità
- Alta 8,8 CVSS 3.1
- Probabilità di attacchi nei prossimi 30 giorni (EPSS)
- 0,9% tra il 39,4% più alto di tutte le vulnerabilità note
- Tipo di debolezza
- CWE-787
- Più dettagli
- NVD · CVE.org · CISA
Tutte le fonti (8)
- 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
Altre falle sfruttate di Linux
| Aggiunto | Vulnerabilità | Prodotto | Gravità | Probabilità di attacco |
|---|---|---|---|---|
| 18 set 2026 | Improper Check for Unusual or Exceptional Conditions | Kernel | Critica 9,8 | 3,3% |
| 18 set 2026 | Race Condition | Kernel | Alta 7,8 | 1,6% |
| 27 ago 2026 | Unspecified | Kernel | Alta 7,8 | 0,7% |
| 26 ago 2026 | Out-of-Bounds Write | Kernel | Alta 7,8 | 8,9% |
| 2 giu 2026 | Improper Authentication | Kernel | Alta 7,8 | 5,5% |
| 1 mag 2026 | Incorrect Resource Transfer Between Spheres | Kernel | Alta 7,8 | 98% |
| 26 gen 2026 | Integer Overflow | Kernel | Alta 7,8 | 15% |
| 6 ott 2025 | Heap Out-of-Bounds Write | Kernel | Alta 8,3 | 79% |
Fonti: Known Exploited Vulnerabilities (CISA, pubblico dominio), CVE records (cve.org) e EPSS (FIRST). La probabilità di attacco è la stima EPSS che qualcuno provi a sfruttare la falla nei prossimi 30 giorni.