What is the CVSS score of EUVD-2026-55571?

EUVD-2026-55571 has a contested CVSS base score of 9.8 from a third party (e.g. CISA-ADP), while the vendor rates it Critical. vuln.today uses the vendor rating as authoritative.

Which versions of Linux Kernel are affected by EUVD-2026-55571?

A Linux kernel bug affecting IBM Z mainframe systems (CVE-2026-68385, rated CVSS 9.8) poses minimal enterprise risk: it targets s390 architecture exclusively, no public exploits have been identified,…. A patch is available.

How to fix or mitigate EUVD-2026-55571?

Within 24 hours, determine whether your organization operates IBM Z mainframe systems; if not, close this alert. For organizations with s390 systems, contact your mainframe infrastructure team within 7 days to identify affected kernel versions against vendor guidance and assess exposure. Within 30 days, coordinate application of the vendor-released patch to all affected s390 systems, prioritizing internet-exposed systems, though real-world risk remains low.

Linux Kernel EUVD-2026-55571

| CVE-2026-68385 CRITICAL

2026-08-10 Linux

GHSA-p69g-gmqr-g4rm

Information Disclosure Linux

Critical

Disputed · 9.8 Vendor: Linux

Severity by source

Sources disagree (Medium–Critical)

Vendor (Linux) PRIMARY

9.8 CRITICAL

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

vuln.today AI

3.6 LOW

Local s390-only path gated on absent vector hardware (AV:L/AC:H); needs local execution (PR:L); worst case is limited address-zero info leak and checksum corruption (C:L/I:L), no availability impact.

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

4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

SUSE

5.5 MEDIUM

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

Red Hat

5.5 MEDIUM

qualitative

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorVendor: Linux

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Aug 14, 2026 - 02:53 vuln.today

CVSS changed

Aug 13, 2026 - 23:37 NVD

9.8 (CRITICAL)

Patch available

Aug 10, 2026 - 14:18 EUVD

CVE Published

Aug 10, 2026 - 12:04 cve.org

CRITICAL 9.8

CVE Published

Aug 10, 2026 - 12:04 cve.org

UNKNOWN (no severity yet)

DescriptionCVE.org

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

s390/checksum: Fix csum_partial() without vector facility

Currently csum_partial() calls csum_copy() with copy=false and dst=NULL. On machines without the vector facility, csum_copy() falls back to cksm(dst, ...), causing the checksum to be calculated from address zero instead of the source buffer.

The VX implementation already checksums data loaded from src. Make the fallback do the same by passing src to cksm().

AnalysisAI

Incorrect checksum computation in the Linux kernel's s390 (IBM Z mainframe) architecture code causes csum_partial() to read from memory address zero instead of the intended source buffer on machines lacking the vector (VX) facility. Affects s390 systems running the buggy kernel builds; the practical effect is corrupted checksums and potential leakage of kernel memory contents near address zero into computed checksums. Rated CVSS 9.8 by automated scoring, but this is a local architecture-specific correctness bug with no public exploit identified at time of analysis and a low EPSS (0.18%, 7th percentile).

Technical ContextAI

The issue lives in the s390 checksum implementation (arch/s390 checksum path) of the Linux kernel. csum_partial() invokes csum_copy() with copy=false and dst=NULL. On CPUs with the vector facility, the VX implementation correctly checksums data loaded from the src pointer. On CPUs without the vector facility, csum_copy() falls back to the hardware cksm instruction using dst (which is NULL/address zero) rather than src, so the checksum is derived from address zero rather than the real source buffer. The CWE is not assigned (N/A), but the root cause is an incorrect pointer/argument being passed to a fallback code path, producing use of an unintended memory address - a logic/pointer-handling defect rather than a classic memory-safety overflow.

RemediationAI

Vendor-released patch: upgrade to a fixed stable kernel - 6.12.101, 6.18.42, 7.1.6, or 7.2-rc4 (or later on the respective branch) - which passes src to cksm() in the fallback so it checksums the correct buffer. The upstream fix is available as stable commits (https://git.kernel.org/stable/c/5fc0a2a6eeb99cac991242bb48796c7749ce3261, .../1d9a2f01b3c4e5c88e06b2db4b5460c2ec884722, .../898bb2814f38399108bdd2113f38d97383a7036a, .../4bb06b60d982355e22647b3d12d6619419f8c1fa); apply the one matching your stable series. As a non-patch note, the defect only manifests on s390 hardware lacking the vector facility, so environments running s390 guests/hosts on VX-capable CPUs are not exposed and can prioritize accordingly; there is no meaningful runtime workaround short of applying the fixed kernel.

Same technique Information Disclosure

View all

CVE-2019-2725 CRITICAL POC

9.8

CVE-2021-34523 CRITICAL POC

9.0

CVE-2013-2251 CRITICAL POC

9.8

CVE-2017-5638 CRITICAL POC

9.8

CVE-2025-24813 CRITICAL POC

9.8

CVE-2015-1701 HIGH POC

7.8

CVE-2017-0147 HIGH POC

7.5

CVE-2014-6324 HIGH POC

8.8

Vendor StatusVendor

SUSE

Severity: Moderate

Product	Status
SUSE Linux Enterprise Desktop 15 SP7	Not-Affected
SUSE Linux Enterprise Desktop 15 SP7	Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7	Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7	Not-Affected
SUSE Linux Enterprise High Availability Extension 16.0	Affected

EUVD-2026-55571 vulnerability details – vuln.today

Back

Linux Kernel EUVD-2026-55571

Severity by source

CVSS VectorVendor: Linux

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

RemediationAI

Same technique Information Disclosure

Vendor StatusVendor

SUSE

Share

External POC / Exploit Code