CVE-2026-89562
ip6_gre: fix hardware header length for NBMA tunnels
Description
In the Linux kernel, the following vulnerability has been resolved: ip6_gre: fix hardware header length for NBMA tunnels ip6gre_tnl_link_config_route() accumulates the lower device's hardware header length into dev->hard_header_len whenever header_ops is set. This is incorrect for both users of header_ops. ip6gretap and ip6erspan have a fixed Ethernet hardware header length. For an NBMA ip6gre tunnel, ip6gre_header() creates only the GRE header, the optional FOU or GUE header, and the outer IPv6 header. The lower device header is headroom needed later, not part of the tunnel device's hardware header. Keep the lower device header in needed_headroom. Set hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, and leave the fixed Ethernet header length unchanged for tap and erspan devices.
INFO
Published Date :
Sept. 11, 2026, 8:19 p.m.
Last Modified :
Sept. 14, 2026, 1:19 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest version.
- Ensure correct hardware header length calculation.
- Verify GRE, FOU, GUE, and outer IPv6 header handling.
References to Advisories, Solutions, and Tools
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CVE-2026-89562.
CWE - Common Weakness Enumeration
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associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-89562
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-89562 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-89562 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 14, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89562.json">CVE-2026-89562</a> Added Reference https://git.kernel.org/stable/c/7719f6e7ed2ffddc2c3bb61f4467b76d49e0af6a Added Reference https://git.kernel.org/stable/c/b1e95e3602d8e112458627f14c6c31c21f2188cb Added Reference https://git.kernel.org/stable/c/c3457a5aae5fb43f7023d3f3dc472c2afa22acf0 Added Reference https://git.kernel.org/stable/c/cb1afd087aedc90e5274537e4fb9bf3f98e5afdb -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 11, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ip6_gre: fix hardware header length for NBMA tunnels ip6gre_tnl_link_config_route() accumulates the lower device's hardware header length into dev->hard_header_len whenever header_ops is set. This is incorrect for both users of header_ops. ip6gretap and ip6erspan have a fixed Ethernet hardware header length. For an NBMA ip6gre tunnel, ip6gre_header() creates only the GRE header, the optional FOU or GUE header, and the outer IPv6 header. The lower device header is headroom needed later, not part of the tunnel device's hardware header. Keep the lower device header in needed_headroom. Set hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, and leave the fixed Ethernet header length unchanged for tap and erspan devices. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89562.json">CVE-2026-89562</a> Added Reference https://git.kernel.org/stable/c/505b6d296c486ef7d1274f279d4c43a172f63224 Added Reference https://git.kernel.org/stable/c/565038b0092f65afe384961c0f548d605bf438b9 Added Reference https://git.kernel.org/stable/c/8bfe746afee38dd6e4348ddcd22d554789dbb9ff Added Reference https://git.kernel.org/stable/c/b8282668d8fa7c61b80e8e4890729031c291a16c