VulnerabilityPublished 3 May 2025Updated 30 Oct 2026

CVE-2025-37799: Linux kernel · vmxnet3: Fix malformed packet sizing in vmxnet3_process_xdp vmxnet3 driver's XDP

Affects Linux kernelSource GCVE Database

Compare

Not known to be exploited · CVSS 8.6 High · fixed in 6.8.0-1046.49~22.04.1 : patch Linux kernel soon.

Data as of 30 Oct 2026, 22:50 UTC

CVSS 3.1 base score

8.6High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 6.8.0-1046.49~22.04.1, 6.8.0-1051.57~22.04.1, 6.8.0-1046.53~22.04.1 +29

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 3 May 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu 25.10linux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questing`Other threats	Affected 6.17.0-1003.3 – 6.17.0-1017.17 10 affected builds	Fixed in–
Ubuntu 24.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=noble`Other threats	Affected <6.8.0-100.100	Fixed in 6.8.0-100.100
Ubuntu 24.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=noble`Other threats	Affected <6.8.0-1046.49	Fixed in 6.8.0-1046.49
Ubuntu 24.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=noble`Other threats	Affected <6.8.0-1046.52	Fixed in 6.8.0-1046.52
Ubuntu 24.04 LTSlinux-azure-6.11`pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=noble`Other threats	Affected 6.11.0-1008.8~24.04.1 – 6.11.0-1018.18~24.04.1 7 affected builds	Fixed in–
Ubuntu 24.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=noble`Other threats	Affected <6.8.0-1046.53	Fixed in 6.8.0-1046.53

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and included in Linux kernel versions 6.8.0-1046.49~22.04.1 and later. Users should update to these fixed kernel versions or later to remediate the vulnerability. No other mitigation is required as the issue is resolved by the official fix.

Description

A vulnerability in the Linux kernel's vmxnet3 network driver caused malformed packet sizing in the XDP handling for packet sizes between 128 and 3,000 bytes. This bug led to packets being padded with uninitialized kernel memory, resulting in oversized packets that could cause MTU-related connectivity issues, such as dropped HTTP requests when using XDP-based load balancing with IPIP encapsulation. The issue was fixed by correcting the packet length handling in the vmxnet3 driver.

Impact

The vulnerability can cause network packets to be malformed with oversized lengths, leaking uninitialized kernel memory contents onto the network. This can disrupt network connectivity due to MTU mismatches, causing dropped packets and service interruptions. Additionally, the leakage of kernel memory data could expose sensitive information. The CVSS score of 8.6 (high severity) reflects the potential for significant confidentiality and availability impact. There is no evidence of known exploitation in the wild.

References

Community reviews

Loading reviews…