CVE-2026-80544High· 7.8▾ Twilight

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Improve EP11 CPRB domain handling with ASN.1 parsing The zcrypt_msgtype6_send_ep11_cprb() function uses fragile struct overlays to access and modify the d…

▾ Twilight zone — High severity, or a signal on a lesser flaw

Depth score43/ 100 · Moderate

impact 42.9 · likelihood 0 · exploitation 0

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Proof of concept

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Published

Aug 26, 2026

Updated

Oct 15, 2026

CVSS

7.8

Vendor

Linux

Product

Linux

CWE

—

Depth score

43 · Moderate

EPSS

0.18% · p8

Platforms

—

Source

NVD

Vector

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

CISA SSVC

decided 2026-10-16

Exploitation: none
Automatable: no
Technical impact: total

Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.

EPSS history

Exploit-prediction probability, daily snapshots since Oct 15.

0.2% → 0.2%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 50 days

Aug 26, 2026Published
Disclosed via NVD
Oct 15, 2026Record revised
Last analysed / modified upstream
Oct 15, 2026EPSS first tracked
0.2%

Linux #nvd #cve.org

Affected

Linux >= 20b0b0159390fa5c00a435195649680fefda81e0 < 00a44ff06bcffb68b9cd7e90d2259b7d14b82b18
Linux >= e2c6d91eb8b1533753755f07803e47eceed263d0 < db21b2cf6dd0af5ffd08931e0a9fcda5a0473220
Linux >= e2c6d91eb8b1533753755f07803e47eceed263d0 < 0864a163783bff109b548266921829ea794edc93
Linux 7.1

Full technical detail▾

Overview

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

s390/zcrypt: Improve EP11 CPRB domain handling with ASN.1 parsing

The zcrypt_msgtype6_send_ep11_cprb() function uses fragile struct overlays to access and modify the domain field in the EP11 CPRB payload, creating maintainability and security concerns:

Struct overlay approach (pld_hdr) assumes fixed payload structure and doesn't validate the actual ASN.1 encoding.
Complex length format detection logic is error-prone and doesn't properly validate bounds at each parsing step.
Direct struct member access bypasses proper ASN.1 validation.

Fix by replacing struct overlays with explicit ASN.1 parsing that validates each field (payload tag/length, function tag/length/value, optional domain tag/length/value) with proper bounds checking at every step. Add asn1_int_encode() helper function to safely write integer values with correct endianness conversion. This makes the code consistent with the validation pattern introduced with the rework of the xcrb_msg_to_type6_ep11cprb_msgx() function.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd#cve.org