CVE-2026-42177: Linux kernel · Improper Access Control
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.8.1 when convenient.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.8.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 12 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Upgrade linux-entra-sso and siemens/linux-entra-sso to 1.8.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| siemenslinux-entra-sso | Affected
| Fixed in
|
GitHubsiemens/linux-entra-ssopkg:github/siemens/linux-entra-ssoOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
This vulnerability is fixed in linux-entra-sso version 1.8.1. Users and administrators should upgrade to version 1.8.1 or later to remediate this issue. Until upgrading, avoid granting broad host permissions to the extension or using it in untrusted browsing contexts.
Description
CVE-2026-42177 is an improper access control vulnerability in the Siemens linux-entra-sso browser plugin for Linux versions prior to 1.8.1. The vulnerability arises because the Chrome adapter registers a broad URL matching rule that attaches the Entra ID Primary Refresh Token (PRT) cookie to requests matching a substring pattern, without properly restricting the URL scope. This can cause the PRT cookie to be sent to attacker-controlled hosts if the URL path embeds the legitimate login URL, potentially exposing sensitive authentication tokens. The issue is fixed in version 1.8.1.