CVE-2026-53266

Aliases:UBUNTU-CVE-2026-53266DEBIAN-CVE-2026-53266CGA-28rx-vrxv-3rq8CGA-4r85-jr53-8c6jCGA-6xw8-wj4g-7gjfCGA-qjv7-2qh5-8f44CGA-w2pg-vhx8-mp37CGA-w869-3pgp-jv24CGA-49cq-w5fx-452qCGA-4w6m-w755-59cgCGA-5393-cxr9-7hh7CGA-6mrw-c4v7-q2m3CGA-6mw6-hc47-5hx7CGA-7qqx-j9vr-5rj3CGA-7rhq-9828-2f8hCGA-7w5c-949c-f4qfCGA-8w3p-w59v-hvp6CGA-97cr-3c7r-247rCGA-98f3-r47x-gx7mCGA-9rv7-pwg6-vqqqCGA-cj9r-639q-rc3rCGA-f52q-c5vr-xh9mCGA-g9x9-m28h-8c6pCGA-hvjj-7p9v-qh8xCGA-j7j9-pmf5-q67xCGA-jg25-3h5w-52jcCGA-jrgp-vphm-3cgvCGA-q69h-jg69-x56wCGA-q9j7-8g7j-qp4mCGA-qpf3-7jvp-r4cmCGA-qqr8-q25q-9jchCGA-qv78-wqx4-542gCGA-vqjc-4frr-x4qcCGA-w4v5-5q2p-w773
Advisory lineage Upstream: 0 Downstream: 23
Analyzed
Published: 25 Jun 2026, 08:39
Last modified:19 Sept 2026, 03:56

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
8.8 HIGH
v3.1 (cve.org)
EPSS Score
0.12% LOW
0% probability 0.00%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

25 Jun 2026, 08:39
Published
Vulnerability first disclosed
18 Sept 2026, 00:00
Added to CISA KEV
Linux Kernel Out-of-Bounds Write Vulnerability
19 Sept 2026, 03:56
Last Modified
Vulnerability information updated
21 Sept 2026, 00:00
CISA Remediation Due
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.

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().

CVSS Metrics

  • v4.0•HIGH•Score: 7.3CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
  • v3.1•HIGH•Score: 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.12%• Percentile: 2%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • chainguard•linux-aws-6.12

    < 6.12.94-r0

  • chainguard•linux-aws-6.18

    < 6.18.36-r0

  • chainguard•linux-azure-6.12

    < 6.12.94-r0

  • chainguard•linux-azure-6.18

    < 6.18.38-r0 | < 6.18.36-r0

  • chainguard•linux-desktop-6.18

    < 6.18.48-r0

  • chainguard•linux-desktop-7.2

    < 7.2.3-r0

  • chainguard•linux-firecracker-6.18

    < 6.18.44-r0

  • chainguard•linux-gcp-6.12

    < 6.12.94-r0

  • chainguard•linux-gcp-6.18

    < 6.18.38-r0 | < 6.18.36-r0

  • chainguard•linux-gcp-6.18-bootc-boot-installed

    < 6.18.38-r0

  • chainguard•linux-qemu-6.12

    < 6.12.94-r0

  • chainguard•linux-qemu-6.18

    < 6.18.38-r0 | < 6.18.36-r0

  • chainguard•linux-qemu-6.18-bootc-boot-installed

    < 6.18.38-r0

  • chainguard•linux-qemu-melange

    < 6.18.38-r0

  • chainguard•linux-qemu-rc

    all

  • chainguard•linux-raspberry-pi

    < 20260724-r0

  • chainguard•linux-raspberry-pi-4

    < 20260911-r0

  • chainguard•linux-vmware-6.12

    < 6.12.94-r0

  • chainguard•linux-vmware-6.18

    < 6.18.36-r0

  • debian•linux

    < 5.10.259-1 | < 6.1.176-1 | < 6.12.94-1 | < 7.0.13-1

  • debian•linux-6.1

    < 6.1.176-1~deb11u1

  • ubuntu•linux

    all | all | all | all | all | < 7.0.0-31.31

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | all | all | all | all | < 7.0.0-1012.12

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    all

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    all

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.14

    all

  • ubuntu•linux-aws-6.17

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    all

  • ubuntu•linux-aws-7.0

    all | < 7.0.0-1012.12~24.04.1

  • ubuntu•linux-aws-fips

    all

  • ubuntu•linux-azure

    all | all | all | all | all | all

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    all

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    all

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    all

  • ubuntu•linux-azure-6.14

    all

  • ubuntu•linux-azure-6.17

    all

Showing first 50 affected entries in server-rendered view.

References (22)