CVE-2025-30334Network attack vector

Kernel crash via incorrect WireGuard packet sizing

Published Mar 20, 2025 · Updated Mar 21, 2025

Incorrect buffer sizing in OpenBSD 7.5 before errata 015 and 7.6 before errata 006 allows remote authenticated users to crash the kernel. The wg_encap() path capped plaintext_len at the peer MTU even though subsequent mbuf handling did not accommodate that truncation, producing inconsistent packet and buffer lengths. Reachability requires a configured WireGuard peer able to send tunnel traffic; successful exploitation interrupts the entire system by crashing its kernel.

CVSS severity7.1
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Incorrect buffer sizing in OpenBSD 7.5 before errata 015 and 7.6 before errata 006 allows remote authenticated users to crash the kernel. The wg_encap() path capped plaintext_len at the peer MTU even though subsequent mbuf handling did not accommodate that truncation, producing inconsistent packet and buffer lengths. Reachability requires a configured WireGuard peer able to send tunnel traffic; successful exploitation interrupts the entire system by crashing its kernel.

The record

CVE
CVE-2025-30334
Published
Mar 20, 2025
Updated
Mar 21, 2025
Vendor
OpenBSD Project
Product
OpenBSD
Classifications
CWE-131, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 20, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.5 <7.5 errata 015
  2. Affected versionversion=7.6 <7.6 errata 006

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenBSD Project · OpenBSDversion=7.5 <7.5 errata 015; version=7.6 <7.6 errata 006

Published CVSS scores

7.1CISA CNACVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
6.5CISA CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-131Incorrect Calculation of Buffer Size
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo