VulnerabilityPublished 8 May 2026Updated 11 May 2026

CVE-2026-43466: Linux kernel · net/mlx5e: Fix DMA FIFO desync on error CQE SQ recovery

Source GCVE Database

Authoritative record:CVE-2026-43466· High 8.2

Not known to be exploited · CVSS 8.2 High · fixed in ce1b19dd0684eeb68a124c11085bd611260b36d9 : patch Linux kernel soon.

Data as of 27 Oct 2026, 01:26 UTC

CVSS 3.1 base score

8.2High

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

Patch: Available – fixed in ce1b19dd0684eeb68a124c11085bd611260b36d9, 1633111d69053512d099658d4a05fc736fab36b0, 829efcccfa8f69db5dc8332961295587d218cee6 +5

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

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

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: None: There is no loss of confidentiality within the impacted component.
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: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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.

ghsa-757p-mh2f-rf8w

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ db75373c91b0cfb6a68ad6ae88721e4e21ae6261, < ce1b19dd0684eeb68a124c11085bd611260b36d9	Fixed in ce1b19dd0684eeb68a124c11085bd611260b36d9
LinuxLinux	Affected ≥ db75373c91b0cfb6a68ad6ae88721e4e21ae6261, < 1633111d69053512d099658d4a05fc736fab36b0	Fixed in 1633111d69053512d099658d4a05fc736fab36b0
LinuxLinux	Affected ≥ db75373c91b0cfb6a68ad6ae88721e4e21ae6261, < 829efcccfa8f69db5dc8332961295587d218cee6	Fixed in 829efcccfa8f69db5dc8332961295587d218cee6
LinuxLinux	Affected ≥ db75373c91b0cfb6a68ad6ae88721e4e21ae6261, < 821f85d619f7f22cda7b9d7de89cf5eeb1d11544	Fixed in 821f85d619f7f22cda7b9d7de89cf5eeb1d11544
LinuxLinux	Affected ≥ db75373c91b0cfb6a68ad6ae88721e4e21ae6261, < 383b37c04a4827ba60b2bafc1a6cdfd995aed58f	Fixed in 383b37c04a4827ba60b2bafc1a6cdfd995aed58f
LinuxLinux	Affected ≥ db75373c91b0cfb6a68ad6ae88721e4e21ae6261, < 9c5ee9b981ee050b73fdf3f4a2464d6f1a8e10a8	Fixed in 9c5ee9b981ee050b73fdf3f4a2464d6f1a8e10a8

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel by removing the reset of the dma_fifo_cc counter during error CQE SQ recovery. Users should update to a Linux kernel version that includes this fix. Since this is a kernel-level issue, applying the official kernel update or patch from the Linux kernel maintainers is the recommended remediation. No additional mitigations are indicated.

Description

CVE-2026-43466 is a high-severity vulnerability in the Linux kernel's mlx5e network driver related to DMA FIFO desynchronization during error completion queue entry (CQE) send queue (SQ) recovery. The flaw occurs because the recovery function resets the DMA FIFO consumer counter but not the producer counter, causing a mismatch that leads to unmapping stale DMA addresses. This issue can trigger kernel warnings and potentially cause denial of service due to improper DMA handling. The vulnerability has been fixed by removing the erroneous reset of the consumer counter during recovery.

Impact

The desynchronization causes the kernel to unmap stale DMA addresses, which can lead to kernel warnings and potentially disrupt normal network driver operation. The CVSS score of 8.2 indicates a high severity with no confidentiality impact, limited integrity impact, and high availability impact, suggesting possible denial of service or system instability. There is no indication of remote code execution or data leakage.

Summary

This vulnerability in the Linux kernel's mlx5e driver involves a desynchronization between the DMA FIFO producer and consumer counters during the recovery flow triggered by a TX error CQE. Specifically, the function mlx5e_reset_txqsq_cc_pc() resets dma_fifo_cc to zero but leaves dma_fifo_pc unchanged, causing the producer to push new DMA entries at an incorrect position while the consumer reads from zero. This leads to unmapping of stale DMA addresses and kernel warnings related to iommu_dma_unmap_page. The fix removes the reset of dma_fifo_cc, aligning with the fact that all work queue entries have been flushed and the counters should remain synchronized.

CWE-662Improper Synchronization (opens in a new tab)
Class weakness
The product utilizes multiple threads, processes, components, or systems to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Implementation
Use industry standard APIs to synchronize your code.
Attack patterns
Leveraging Race Conditions via Symbolic Links (opens in a new tab)
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
Forced Deadlock (opens in a new tab)
Leveraging Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Oct 2026, 01:26 UTC

WeaknessesCWE-662

Technical details

References

Community reviews

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