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NVD / CVE Program· CNA Linux

CVE-2025-40248: vsock: Ignore signal/timeout on connect() if already established

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: 0.15% (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 002541ef650b742a198e4be363881439bb9d86b4, 3f71753935d648082a8279a97d30efe6b85be680, 5998da5a8208ae9ad7838ba322bccb2bdcd95e81.

Low priority for now. Upgrade to Linux Linux 002541ef650b742a198e4be363881439bb9d86b4, 3f71753935d648082a8279a97d30efe6b85be680, 5998da5a8208ae9ad7838ba322bccb2bdcd95e81 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: vsock: Ignore signal/timeout on connect() if already established During connect(), acting on a signal/timeout by disconnecting an already established socket leads to several issues: 1. connect() invoking vsock_transport_cancel_pkt() -> virtio_transport_purge_skbs() may race with sendmsg() invoking virtio_transport_get_credit(). This results in a permanently elevated `vvs->bytes_unsent`. Which, in turn, confuses the SOCK_LINGER handling. 2. connect() resetting a connected socket's state may race with socket being placed in a sockmap. A disconnected socket remaining in a sockmap breaks sockmap's assumptions. And gives rise to WARNs. 3. connect() transitioning SS_CONNECTED -> SS_UNCONNECTED allows for a transport change/drop after TCP_ESTABLISHED. Which poses a problem for any simultaneous sendmsg() or connect() and may result in a use-after-free/null-ptr-deref. Do not disconnect socket on signal/timeout. Keep the logic for unconnected sockets: they don't linger, can't be placed in a sockmap, are rejected by sendmsg(). [1]: https://lore.kernel.org/netdev/e07fd95c-9a38-4eea-9638-133e38c2ec9b@rbox.co/ [2]: https://lore.kernel.org/netdev/20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co/ [3]: https://lore.kernel.org/netdev/60f1b7db-3099-4f6a-875e-af9f6ef194f6@rbox.co/

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Dec 4, 2025
Updated
Oct 19, 2026
EPSS
0.1% · 4th 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%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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

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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

    • 3.9affected
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before 3f71753935d648082a8279a97d30efe6b85be680affected · git
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before da664101fb4a0de5cb70d2bae6a650df954df2afaffected · git
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before 67432915145848658149683101104e32f9fd6559affected · git
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before eeca93f06df89be5a36305b7b9dae1ed65550dfcaffected · git
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before 5998da5a8208ae9ad7838ba322bccb2bdcd95e81affected · git
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before f1c170cae285e4b8f61be043bb17addc3d0a14b5affected · git
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before ab6b19f690d89ae4709fba73a3c4a7911f495b7aaffected · git
    • d021c344051af91f42c5ba9fdedc176740cbd238 and later · before 002541ef650b742a198e4be363881439bb9d86b4affected · git
    • before 3.9not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-124.31.1.el10_16.12.0-124.31.1.el10_1
AlmaLinux:10kernel-docbefore 6.12.0-124.31.1.el10_16.12.0-124.31.1.el10_1
AlmaLinux:8bpftoolbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.97.1.el8_104.18.0-553.97.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.97.1.rt7.438.el8_104.18.0-553.97.1.rt7.438.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.97.1.rt7.438.el8_104.18.0-553.97.1.rt7.438.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.97.1.rt7.438.el8_104.18.0-553.97.1.rt7.438.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.97.1.rt7.438.el8_104.18.0-553.97.1.rt7.438.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.97.1.rt7.438.el8_104.18.0-553.97.1.rt7.438.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.97.1.rt7.438.el8_104.18.0-553.97.1.rt7.438.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.97.1.rt7.438.el8_104.18.0-553.97.1.rt7.438.el8_10

+96

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-2025-40246Dec 4, 2025 · xfs: fix out of bounds memory read error in symlink repair
    0Monitor
  • ← EarlierCVE-2025-40247Dec 4, 2025 · drm/msm: Fix pgtable prealloc error path
    0Monitor
  • Later →CVE-2025-40249Dec 4, 2025 · gpio: cdev: make sure the cdev fd is still active before emitting events
    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 Linux002541ef650b742a198e4be363881439bb9d86b4Vendor (CNA)
Linux Linux3f71753935d648082a8279a97d30efe6b85be680Vendor (CNA)
Linux Linux5998da5a8208ae9ad7838ba322bccb2bdcd95e81Vendor (CNA)
Linux Linux67432915145848658149683101104e32f9fd6559Vendor (CNA)
Linux Linuxab6b19f690d89ae4709fba73a3c4a7911f495b7aVendor (CNA)
Linux Linuxda664101fb4a0de5cb70d2bae6a650df954df2afVendor (CNA)
Linux Linuxeeca93f06df89be5a36305b7b9dae1ed65550dfcVendor (CNA)
Linux Linuxf1c170cae285e4b8f61be043bb17addc3d0a14b5Vendor (CNA)
almalinux:bpftool4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.97.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.159-1 · Debian:12Package registry (OSV)
debian:linux-6.16.1.159-1~deb11u1 · Debian:11Package registry (OSV)
red hat:bpftool0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-core0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-debuginfo0:4.18.0-553.97.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+6

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.

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).

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.

Change log

  1. Fix✗ → ✓

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

References

Show all references (8 more)

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

All records