Description
In the Linux kernel, the following vulnerability has been resolved:

IB/mad: Drop unmatched RMPP responses before reassembly

Kernel-handled RMPP receive processing starts reassembly for active
DATA responses before the response is matched to an outstanding send.
The normal match happens later, after ib_process_rmpp_recv_wc() has
either assembled a complete message or consumed the segment.

That ordering lets an unsolicited response that routes to a kernel
RMPP agent by the high TID bits allocate or extend RMPP receive state
before the full TID and source address are checked against a real
request. A reordered burst can therefore reach the receive-side
insertion path even though the response would not match any send.

For kernel-handled RMPP DATA responses, require the existing
ib_find_send_mad() match before entering RMPP reassembly. The matcher
already checks the full TID, management class and source address/GID
against the agent wait, backlog and in-flight send lists. If there is
no match, drop the response without creating RMPP state.

This leaves the RMPP window behavior unchanged and only rejects
responses that have no corresponding request.
Published: 2026-08-10
Score: 7.1 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

Kernel‑handled Remote Management Messaging Protocol (RMPP) responses are reassembled before they are matched to an existing send request. The code first allocates or extends receive state for each inbound RMPP data segment, only dropping the response later if no matching send can be found. This ordering allows an attacker to send unsolicited RMPP packets that are accepted for state allocation, potentially exhausting kernel memory or processing resources. The flaw is a resource exhaustion vulnerability that can lead to denial of service. No code execution or privilege escalation is indicated in the description, and no vulnerability comment or advisory mentions such effects, so any claim of remote code execution would be speculative and is not supported by the provided data.

Affected Systems

The vulnerability applies to all Linux kernel builds that include IB/mad RMPP handling. The CPE string indicates a generic Linux kernel, and no specific version range is listed in the provided data. Consequently, any installed kernel that supports RMPP processing is potentially affected until the patch that drops unmatched responses is applied.

Risk and Exploitability

The CVSS score of 7.1 indicates high severity, the EPSS score of < 1% suggests a low probability of exploitation, and the flaw is not included in the CISA KEV catalog. It is inferred that an attacker can trigger the flaw by sending crafted RMPP packets over the network to a target system with RMPP enabled. Because the flaw requires no privileged local access and can be triggered by external traffic, the likely attack vector is remote network. The absence of memory corruption or privilege‑escalation details in the description means no confirmed remote code execution capability is known, and the risk is dominated by potential denial of service through resource exhaustion.

Generated by OpenCVE AI on August 14, 2026 at 02:15 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the kernel update that contains the patch to drop unmatched RMPP responses before reassembly
  • If an update is not currently available, reconfigure the kernel to disable the RMPP feature so that unsolicited RMPP traffic is ignored
  • Implement network filtering or rate limiting to block or reduce inbound RMPP packets from untrusted sources

Generated by OpenCVE AI on August 14, 2026 at 02:15 UTC.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Debian DLA Debian DLA DLA-4745-1 linux-6.12 security update
History

Wed, 19 Aug 2026 16:45:00 +0000


Fri, 14 Aug 2026 01:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-368
CWE-770

Thu, 13 Aug 2026 23:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H'}


Wed, 12 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-179
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important


Mon, 10 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-368
CWE-770

Mon, 10 Aug 2026 12:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: IB/mad: Drop unmatched RMPP responses before reassembly Kernel-handled RMPP receive processing starts reassembly for active DATA responses before the response is matched to an outstanding send. The normal match happens later, after ib_process_rmpp_recv_wc() has either assembled a complete message or consumed the segment. That ordering lets an unsolicited response that routes to a kernel RMPP agent by the high TID bits allocate or extend RMPP receive state before the full TID and source address are checked against a real request. A reordered burst can therefore reach the receive-side insertion path even though the response would not match any send. For kernel-handled RMPP DATA responses, require the existing ib_find_send_mad() match before entering RMPP reassembly. The matcher already checks the full TID, management class and source address/GID against the agent wait, backlog and in-flight send lists. If there is no match, drop the response without creating RMPP state. This leaves the RMPP window behavior unchanged and only rejects responses that have no corresponding request.
Title IB/mad: Drop unmatched RMPP responses before reassembly
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-19T16:35:19.996Z

Reserved: 2026-07-30T09:28:09.392Z

Link: CVE-2026-68425

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-10T13:20:36.413

Modified: 2026-08-19T17:20:49.477

Link: CVE-2026-68425

cve-icon Redhat

Severity : Important

Publid Date: 2026-08-10T12:04:45Z

Links: CVE-2026-68425 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-14T02:30:17Z

Weaknesses
  • CWE-179

    Incorrect Behavior Order: Early Validation