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NVD / CVE Program· CNA Linux

CVE-2025-21854: sockmap, vsock: For connectible sockets allow only connected

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.23% (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 22b683217ad2112791a708693cb236507abd637a, 8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f, cc9a7832ede53ade1ba9991f0e27314caa4029d8; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1.

Low priority for now. Upgrade to Linux Linux 22b683217ad2112791a708693cb236507abd637a, 8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f, cc9a7832ede53ade1ba9991f0e27314caa4029d8; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1 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: sockmap, vsock: For connectible sockets allow only connected sockmap expects all vsocks to have a transport assigned, which is expressed in vsock_proto::psock_update_sk_prot(). However, there is an edge case where an unconnected (connectible) socket may lose its previously assigned transport. This is handled with a NULL check in the vsock/BPF recv path. Another design detail is that listening vsocks are not supposed to have any transport assigned at all. Which implies they are not supported by the sockmap. But this is complicated by the fact that a socket, before switching to TCP_LISTEN, may have had some transport assigned during a failed connect() attempt. Hence, we may end up with a listening vsock in a sockmap, which blows up quickly: KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+ Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Call Trace: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x35a/0x700 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 For connectible sockets, instead of relying solely on the state of vsk->transport, tell sockmap to only allow those representing established connections. This aligns with the behaviour for AF_INET and AF_UNIX.

Published
Mar 12, 2025
Updated
Jun 17, 2026
EPSS
0.2% · 14th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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

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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.

VendorProduct
linuxlinux kernel

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
    • 634f1a7110b439c65fd8a809171c1d2d28bcea6f and later · before cc9a7832ede53ade1ba9991f0e27314caa4029d8affected · git
    • 634f1a7110b439c65fd8a809171c1d2d28bcea6f and later · before 22b683217ad2112791a708693cb236507abd637aaffected · git
    • 634f1a7110b439c65fd8a809171c1d2d28bcea6f and later · before f7b473e35986835cc2813fef7b9d40336a09247eaffected · git
    • 634f1a7110b439c65fd8a809171c1d2d28bcea6f and later · before 8fb5bb169d17cdd12c2dcc2e96830ed487d77a0faffected · git
    • before 6.4not affected · semver
    • 6.6.80 and later · up to and including 6.6.*not affected · semver
    • 6.12.17 and later · up to and including 6.12.*not affected · semver
    • 6.13.5 and later · up to and including 6.13.*not affected · semver
    • 6.14 and laternot affected · original_commit_for_fix
Affected versions · NVD (4)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.4 and later · before 6.6.80
  • linux linux kernel6.7 and later · before 6.12.17
  • linux linux kernel6.13 and later · before 6.13.5
  • linux linux kernel6.14

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.17-16.12.17-1
openSUSE:Leap 15.6dtb-aarch64before 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-64kbbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-azurebefore 6.4.0-150600.8.48.16.4.0-150600.8.48.1
openSUSE:Leap 15.6kernel-debugbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-defaultbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-default-basebefore 6.4.0-150600.23.65.1.150600.12.28.46.4.0-150600.23.65.1.150600.12.28.4
openSUSE:Leap 15.6kernel-docsbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-kvmsmallbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-obs-buildbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-obs-qabefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-sourcebefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-source-azurebefore 6.4.0-150600.8.48.16.4.0-150600.8.48.1
openSUSE:Leap 15.6kernel-symsbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
openSUSE:Leap 15.6kernel-syms-azurebefore 6.4.0-150600.8.48.16.4.0-150600.8.48.1
openSUSE:Leap 15.6kernel-zfcpdumpbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
SUSE:Linux Enterprise Live Patching 15 SP6kernel-livepatch-SLE15-SP6_Update_14before 1-150600.13.3.41-150600.13.3.4
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7_Update_3before 1-150700.15.3.41-150700.15.3.4
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-64kbbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-defaultbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-default-basebefore 6.4.0-150600.23.65.1.150600.12.28.46.4.0-150600.23.65.1.150600.12.28.4
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-sourcebefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-zfcpdumpbefore 6.4.0-150600.23.65.16.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-64kbbefore 6.4.0-150700.53.11.16.4.0-150700.53.11.1

+16

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-21851Mar 12, 2025 · bpf: Fix softlockup in arena_map_free on 64k page kernel
    13Monitor
  • ← EarlierCVE-2025-21852Mar 12, 2025 · net: Add rx_skb of kfree_skb to raw_tp_null_args[].
    22Monitor
  • Later →CVE-2025-21855Mar 12, 2025 · ibmvnic: Don't reference skb after sending to VIOS
    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 Linux22b683217ad2112791a708693cb236507abd637aVendor (CNA)
Linux Linux8fb5bb169d17cdd12c2dcc2e96830ed487d77a0fVendor (CNA)
Linux Linuxcc9a7832ede53ade1ba9991f0e27314caa4029d8Vendor (CNA)
Linux Linuxf7b473e35986835cc2813fef7b9d40336a09247eVendor (CNA)
azl3 kernel 6.6.78.1-3 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.82.1-1 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.12.17-1 · Debian:13Package registry (OSV)
opensuse:dtb-aarch646.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-64kb6.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-azure6.4.0-150600.8.48.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-debug6.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default6.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default-base6.4.0-150600.23.65.1.150600.12.28.4 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-docs6.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-kvmsmall6.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-build6.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-qa6.4.0-150600.23.65.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-source-azure6.4.0-150600.8.48.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-syms-azure6.4.0-150600.8.48.1 · openSUSE:Leap 15.6Package registry (OSV)
suse:kernel-64kb6.4.0-150600.23.65.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-azure6.4.0-150600.8.48.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6Package registry (OSV)
suse:kernel-default6.4.0-150600.23.65.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-default-base6.4.0-150600.23.65.1.150600.12.28.4 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-docs6.4.0-150600.23.65.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP6Package registry (OSV)
suse:kernel-livepatch-SLE15-SP6_Update_141-150600.13.3.4 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)
suse:kernel-obs-build6.4.0-150600.23.65.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP6Package registry (OSV)
suse:kernel-source6.4.0-150600.23.65.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-source-azure6.4.0-150600.8.48.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6Package registry (OSV)
suse:kernel-syms6.4.0-150600.23.65.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP6Package registry (OSV)
suse:kernel-syms-azure6.4.0-150600.8.48.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6Package registry (OSV)

+1

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.

Not on record for this CVE: EPSS history · 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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

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

nvd-primary

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 (3 more)

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

All records