PatchDayAlert
Daily Digest · 2 min read · 5 CVEs · Issue 89 By PatchDayAlert

Linux kernel privesc and ownCloud auth bypass both exploited in the wild

3 actively exploited bugs today: a Linux IPv6 privilege escalation, a JFrog Artifactory path traversal, and an ownCloud file-access bypass needing zero authentication. Plus an 8.8 Outlook RCE and a SharePoint code injection waiting in the wings.

Patch now
2
Within 24h
2
This week
1
Exploited
3
Linux KernelLinuxJFrog ArtifactoryWindowsOwnCloudMicrosoft OutlookMicrosoft 365 AppsMicrosoft Office 2019Microsoft Office LTSC 2021Microsoft SharePoint

Three bugs are already exploited in the wild right now, and two more are sitting at CVSS 8.8 waiting their turn. The headliner is a privilege escalation in the Linux kernel's IPv6 stack (CVE-2026-53362) with sparse details but confirmed exploitation, so check your distro's advisory and patch your Linux hosts first.


Today's CVEs

Sorted by urgency

02

CVE-2026-66384

CISA KEV
CVSS EPSS 0.26%
Patch within 24h UNSCORED EXPLOITED
JFrog ArtifactoryLinuxWindows

An authenticated user on JFrog Artifactory can write files outside the intended Docker cache directory when specific remote-repository conditions are met. This is a path traversal bug, and it's being exploited in the wild. The auth requirement lowers the risk a bit, but any user with repo access could potentially overwrite critical files on the Artifactory server.

Affected estate
Teams running self-hosted JFrog Artifactory instances with Docker remote repositories configured
How to check
Check your Artifactory version in the Admin panel or via the REST API endpoint '/api/system/version'. Compare against JFrog's security advisory for patched versions.
Included because
exploited in the wild; path traversal; authenticated but common access level; artifact repositories are high-value targets
Action
Upgrade Artifactory to the latest patched release. Audit the Docker cache directory for any files written outside the expected path.
Why it matters
An authenticated attacker can write arbitrary files on your Artifactory server, potentially overwriting configs or planting malicious artifacts.

Evidence trail

03

CVE-2023-49105

CISA KEV
CVSS EPSS 11.07%
Patch now UNSCORED EXPLOITED
OwnCloudLinux

If you run ownCloud and a user doesn't have a signing key configured, an attacker who knows that user's username can access, modify, or delete any of their files with zero authentication. No password, no token, nothing. This is exploited in the wild, and the EPSS score is at the 96th percentile, meaning exploit activity is well above average.

Affected estate
Anyone running self-hosted ownCloud instances
How to check
Check your ownCloud version via the admin panel or 'occ status' command. Review user accounts for missing signing-key configurations.
Included because
unauthenticated; exploited in the wild; EPSS 96th percentile; internet-facing file sharing platform; trivial exploitation requirements
Action
Upgrade ownCloud to the patched release. Immediately enforce signing keys on all user accounts to close the unauthenticated access path.
Why it matters
Unauthenticated file access, modification, and deletion. An attacker only needs to know a username to own that user's entire file store.

Evidence trail

04

CVE-2026-70329

MSRC
8.8
CVSS EPSS 0.67%
Patch within 24h HIGH
Microsoft OutlookMicrosoft 365 AppsMicrosoft Office 2019Microsoft Office LTSC 2021Windows

An integer overflow in Outlook lets an attacker execute code over the network without needing valid credentials. The CVSS 8.8 reflects how little effort this takes: send a crafted message or calendar invite, and code runs in the context of the victim. Not yet exploited in the wild, but network-accessible RCE in Outlook is a magnet for attackers.

Affected estate
Anyone running Microsoft 365 Apps, Office 2019, or Office LTSC 2021 (32-bit or 64-bit)
How to check
Open any Office app, go to File > Account > About, and check the build number. Compare against Microsoft's security update guide for the patched build.
Included because
unauthenticated; network-accessible RCE; CVSS 8.8; extremely common product; email is the top attack vector
Action
Deploy the latest Office security update via WSUS, Intune, SCCM, or Windows Update. Target externally-facing mailbox endpoints first.
Why it matters
Network-based remote code execution in Outlook. An attacker doesn't need credentials, just the ability to send you a message.
Source
Microsoft Security Update Guide

Evidence trail

05

CVE-2026-65660

MSRC
8.8
CVSS EPSS 0.74%
Patch this week HIGH
Microsoft SharePointWindows

A code injection bug in SharePoint lets an authenticated attacker execute arbitrary code on the server over the network. The CVSS 8.8 and "authorized attacker" language mean you need valid SharePoint credentials, but any authenticated user could potentially take over the server. Not yet exploited in the wild.

Affected estate
SharePoint admins running SharePoint Server 2016, 2019, or Subscription Edition on-prem
How to check
Open SharePoint Central Administration > Upgrade and Migration > Check product and patch installation status. Compare the installed build number against Microsoft's advisory.
Included because
authenticated; network-accessible code execution; CVSS 8.8; common enterprise product; on-prem SharePoint is a high-value target
Action
Apply the SharePoint cumulative update or security patch from Microsoft. Audit SharePoint user accounts and tighten permissions to limit who could exploit this.
Why it matters
Authenticated code execution on your SharePoint server. Any user with valid credentials could potentially run arbitrary code on the box.
Source
Microsoft Security Update Guide

Evidence trail


One email, every Wednesday morning.

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