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NVD / CVE Program· CNA Linux

CVE-2026-80989: net: thunderbolt: Mark the connection down when bringing it up fails

Noroxi assessment

Priority: Monitor (action score 35/100)

  • 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: 0.34% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 3c8b26ebf525ba5960510f48c6e9936a79ebe76f, c18f4ce9e2cb8836c302ef30a1e3392a0233c7b3, d6c0af293129345a17dc31c9b4179dc7f3d6af7a.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 3c8b26ebf525ba5960510f48c6e9936a79ebe76f, c18f4ce9e2cb8836c302ef30a1e3392a0233c7b3, d6c0af293129345a17dc31c9b4179dc7f3d6af7a 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: net: thunderbolt: Mark the connection down when bringing it up fails Every failure path in tbnet_connected_work() undoes its own work and returns without clearing login_sent, so the connection still looks established. The next tbnet_tear_down() therefore takes its main branch and repeats a teardown that already happened: it stops rings that are already stopped, which is a dev_WARN() and fatal under panic_on_warn, and it releases net->remote_transmit_path even on the HopID mismatch path, where this connection never owned that id, silently freeing one that someone else is still using. Clear login_sent on those paths. That is enough for tbnet_tear_down() to leave the unwound state alone, and login_received has to stay set: it records that the peer has logged in and carries the transmit path it gave us, which nothing on this side can make the peer send again. Two things change beyond keeping the teardown out of the way: the logout request in that block is no longer sent, and the peer's next login request now re-queues our login work rather than connected_work, giving the connection a fresh login instead of a retry on stale state.

HighCVSS 8.8 · v3.1—No exploit Fix available
Published
Sep 11, 2026
Updated
Oct 30, 2026
EPSS
0.3% · 27th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.8
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.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-80989

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • 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

    • 4.15affected
    • e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e and later · before c18f4ce9e2cb8836c302ef30a1e3392a0233c7b3affected · git
    • e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e and later · before e0d4a17afde5aa0045dc3e1d66c6bb80927bad8caffected · git
    • e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e and later · before ed1d6e3d735e7b03f43a02f4306c89eb7663da14affected · git
    • e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e and later · before f01e6a35c440b62f060e21f36b385e574a7f308caffected · git
    • e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e and later · before d6c0af293129345a17dc31c9b4179dc7f3d6af7aaffected · git
    • e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e and later · before 3c8b26ebf525ba5960510f48c6e9936a79ebe76faffected · git
    • before 4.15not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.157 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
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-2026-80987Sep 11, 2026 · NTB: ntb_transport: Reject oversized TX buffers
    30Monitor
  • ← EarlierCVE-2026-80988Sep 11, 2026 · NTB: ntb_transport: Fail TX enqueue when the QP link is down
    0Monitor
  • Later →CVE-2026-80990Sep 11, 2026 · net: thunderbolt: Release the Rx HopID that was handed out on mismatch
    0Monitor

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 Linux3c8b26ebf525ba5960510f48c6e9936a79ebe76fVendor (CNA)
Linux Linuxc18f4ce9e2cb8836c302ef30a1e3392a0233c7b3Vendor (CNA)
Linux Linuxd6c0af293129345a17dc31c9b4179dc7f3d6af7aVendor (CNA)
Linux Linuxe0d4a17afde5aa0045dc3e1d66c6bb80927bad8cVendor (CNA)
Linux Linuxed1d6e3d735e7b03f43a02f4306c89eb7663da14Vendor (CNA)
Linux Linuxf01e6a35c440b62f060e21f36b385e574a7f308cVendor (CNA)
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).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

Technical details

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • 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
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/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.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

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

All records