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NVD / CVE Program· CNA Linux

CVE-2025-68775: net/handshake: duplicate handshake cancellations leak socket

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.54% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 011ae80c49d9bfa5b4336f8bd387cd25c7593663, 15564bd67e2975002f2a8e9defee33e321d3183f, 3c330f1dee3cd92b57e19b9d21dc8ce5970b09be; azl3 kernel 6.6.119.3-3 on Azure Linux 3.0 6.6.121.1-1.

Low priority for now. Upgrade to Linux Linux 011ae80c49d9bfa5b4336f8bd387cd25c7593663, 15564bd67e2975002f2a8e9defee33e321d3183f, 3c330f1dee3cd92b57e19b9d21dc8ce5970b09be; azl3 kernel 6.6.119.3-3 on Azure Linux 3.0 6.6.121.1-1 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: net/handshake: duplicate handshake cancellations leak socket When a handshake request is cancelled it is removed from the handshake_net->hn_requests list, but it is still present in the handshake_rhashtbl until it is destroyed. If a second cancellation request arrives for the same handshake request, then remove_pending() will return false... and assuming HANDSHAKE_F_REQ_COMPLETED isn't set in req->hr_flags, we'll continue processing through the out_true label, where we put another reference on the sock and a refcount underflow occurs. This can happen for example if a handshake times out - particularly if the SUNRPC client sends the AUTH_TLS probe to the server but doesn't follow it up with the ClientHello due to a problem with tlshd. When the timeout is hit on the server, the server will send a FIN, which triggers a cancellation request via xs_reset_transport(). When the timeout is hit on the client, another cancellation request happens via xs_tls_handshake_sync(). Add a test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED) in the pending cancel path so duplicate cancels can be detected.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Jan 13, 2026
Updated
Oct 19, 2026
EPSS
0.5% · 45th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
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.

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When you'll hear from us

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  • 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

    • 6.4affected
    • 3b3009ea8abb713b022d94fba95ec270cf6e7eae and later · before 011ae80c49d9bfa5b4336f8bd387cd25c7593663affected · git
    • 3b3009ea8abb713b022d94fba95ec270cf6e7eae and later · before e1641177e7fb48a0a5a06658d4aab51da6656659affected · git
    • 3b3009ea8abb713b022d94fba95ec270cf6e7eae and later · before 3c330f1dee3cd92b57e19b9d21dc8ce5970b09beaffected · git
    • 3b3009ea8abb713b022d94fba95ec270cf6e7eae and later · before 15564bd67e2975002f2a8e9defee33e321d3183faffected · git
    • before 6.4not affected · semver
    • 6.6.120 and later · up to and including 6.6.*not affected · semver
    • 6.12.64 and later · up to and including 6.12.*not affected · semver
    • 6.18.3 and later · up to and including 6.18.*not affected · semver
    • 6.19 and laternot affected · original_commit_for_fix

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.69-16.12.69-1
Debian:14linuxbefore 6.18.3-16.18.3-1

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-2025-68770Jan 13, 2026 · bnxt_en: Fix XDP_TX path
    30Monitor
  • ← EarlierCVE-2025-68773Jan 13, 2026 · spi: fsl-cpm: Check length parity before switching to 16 bit mode
    0Monitor
  • Later →CVE-2025-68776Jan 13, 2026 · net/hsr: fix NULL pointer dereference in prp_get_untagged_frame()
    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 Linux011ae80c49d9bfa5b4336f8bd387cd25c7593663Vendor (CNA)
Linux Linux15564bd67e2975002f2a8e9defee33e321d3183fVendor (CNA)
Linux Linux3c330f1dee3cd92b57e19b9d21dc8ce5970b09beVendor (CNA)
Linux Linuxe1641177e7fb48a0a5a06658d4aab51da6656659Vendor (CNA)
azl3 kernel 6.6.119.3-3 on Azure Linux 3.06.6.121.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.12.69-1 · Debian:13Package 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.

No history yet (it accumulates with the daily EPSS job).

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.

  • CVE-2026-68149209 days apartfs: preserve ACL_DONT_CACHE state in forget_cached_acl()
    33Monitor
  • CVE-2026-72057214 days apartnet/sched: act_ct: preserve tc_skb_cb across defragmentation
    32Monitor
  • CVE-2026-64556197 days apartperf/core: Detach event groups during remove_on_exec
    31Monitor
  • CVE-2026-68404209 days apartwifi: cfg80211: use wiphy work for socket owner autodisconnect
    31Monitor
  • CVE-2026-68103209 days apartdrm/amdgpu: reject mapping a reserved doorbell to a new queue
    28Monitor

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).

Technical details

Attack conditions

  • Anyone who can reach it over the internet 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
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-662 · Improper Synchronization

CVSS vector

CVSS:3.1/AV:N/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.

Change log

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

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

References

Show all references (3 more)

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

All records