CVE-2026-80544

Kernel code execution via EP11 payload overlay

Published Aug 26, 2026 · Updated Aug 27, 2026

Out-of-bounds write in Linux kernel 7.1 through 7.1.9 allows local users to corrupt kernel memory via a crafted EP11 CPRB. zcrypt_msgtype6_send_ep11_cprb() overlays a fixed pld_hdr on ASN.1 data and writes dom_val at a miscalculated offset when the domain field is absent or variably encoded. Access to a zcrypt character device on an IBM Z system with an EP11 adapter is required, and exploitation grants kernel code execution or causes a kernel panic.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds write in Linux kernel 7.1 through 7.1.9 allows local users to corrupt kernel memory via a crafted EP11 CPRB. zcrypt_msgtype6_send_ep11_cprb() overlays a fixed pld_hdr on ASN.1 data and writes dom_val at a miscalculated offset when the domain field is absent or variably encoded. Access to a zcrypt character device on an IBM Z system with an EP11 adapter is required, and exploitation grants kernel code execution or causes a kernel panic.

The record

CVE
CVE-2026-80544
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-805, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.1
  2. Affected versionversion=e2c6d91eb8b1533753755f07803e47eceed263d0 <0864a163783bff109b548266921829ea794edc93
  3. Affected versionversion=e2c6d91eb8b1533753755f07803e47eceed263d0 <db21b2cf6dd0af5ffd08931e0a9fcda5a0473220

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=7.1; version=e2c6d91eb8b1533753755f07803e47eceed263d0 <0864a163783bff109b548266921829ea794edc93; version=e2c6d91eb8b1533753755f07803e47eceed263d0 <db21b2cf6dd0af5ffd08931e0a9fcda5a0473220

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-805Buffer Access with Incorrect Length Value
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo