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NVD / CVE Program· CNA Linux

CVE-2026-89562: ip6_gre: fix hardware header length for NBMA tunnels

HighCVSS 7.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 4.20, 5.10, 5.5; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 4.20, 5.10, 5.5; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published
Sep 11, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 2th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • A fix has been released

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Follow CVE-2026-89562

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • cf3d9717a5271573fa193c4dfa0df856295d5b15, 187a6daf5db45adc807c85bbe285319107bed198, d9897bb66ce989325b4bf4cdbb6a799e4ac878b6, 5.10affected
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before cb1afd087aedc90e5274537e4fb9bf3f98e5afdbaffected · git
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before 7719f6e7ed2ffddc2c3bb61f4467b76d49e0af6aaffected · git
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before b1e95e3602d8e112458627f14c6c31c21f2188cbaffected · git
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before c3457a5aae5fb43f7023d3f3dc472c2afa22acf0affected · git
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before 8bfe746afee38dd6e4348ddcd22d554789dbb9ffaffected · git
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before b8282668d8fa7c61b80e8e4890729031c291a16caffected · git
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before 565038b0092f65afe384961c0f548d605bf438b9affected · git
    • 832ba596494b2c9eac7760259eff2d8b7dcad0ee and later · before 505b6d296c486ef7d1274f279d4c43a172f63224affected · git
    • 4.19.162 and later · before 4.20affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-89560Sep 11, 2026 · landlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creation
    33Monitor
  • ← EarlierCVE-2026-89561Sep 11, 2026 · ipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()
    30Monitor
  • Later →CVE-2026-89563Sep 11, 2026 · ip6_tunnel: use skb_cow_head() in ip6_tnl_xmit()
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux4.20Vendor (CNA)
Linux Linux5.10Vendor (CNA)
Linux Linux5.5Vendor (CNA)
Linux Linux505b6d296c486ef7d1274f279d4c43a172f63224Vendor (CNA)
Linux Linux565038b0092f65afe384961c0f548d605bf438b9Vendor (CNA)
Linux Linux7719f6e7ed2ffddc2c3bb61f4467b76d49e0af6aVendor (CNA)
Linux Linux8bfe746afee38dd6e4348ddcd22d554789dbb9ffVendor (CNA)
Linux Linuxb1e95e3602d8e112458627f14c6c31c21f2188cbVendor (CNA)
Linux Linuxb8282668d8fa7c61b80e8e4890729031c291a16cVendor (CNA)
Linux Linuxc3457a5aae5fb43f7023d3f3dc472c2afa22acf0Vendor (CNA)
Linux Linuxcb1afd087aedc90e5274537e4fb9bf3f98e5afdbVendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records