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Last updated: May 13, 2026 at 5:42 AM UTC
All 208 Vulnerability 72 Breach 41 Threat 88 Defense 7
Tag: actively-exploited (29 articles)Clear

Mr_Rot13 actor exploits cPanel CVE-2026-41940 to deploy cross-platform 'Filemanager' backdoor

QiAnXin XLab has tied the ongoing exploitation of cPanel's CVE-2026-41940 to a previously-quiet threat actor it tracks as Mr_Rot13, who has been operating since at least 2020. The attack chain exploits the cPanel and WHM authentication bypass to drop a Go-based infector that adds an attacker SSH key, plants a PHP web shell, and serves a fake login page to steal cPanel credentials (ROT13-encoded, exfiltrated to wrned[.]com). The final payload is a cross-platform backdoor called Filemanager that runs on Windows, macOS, and Linux. XLab counts over 2,000 attacker source IPs currently scanning for this flaw.

Check
Search cPanel and WHM authentication logs for unusual successful logins since April 28. Check /root/.ssh/authorized_keys on every cPanel host for unknown public keys, and search web roots for unfamiliar PHP files.
Affected
Any cPanel or WHM installation that was not patched against CVE-2026-41940 between disclosure on April 28, 2026, and now. Indicators of Mr_Rot13 compromise include the SSH public key added under root, the wrned[.]com credential exfiltration domain, the cp.dene[.]de[.]com infector source, and the wpsock[.]com Filemanager delivery domain.
Fix
If still unpatched, install the cPanel fix for CVE-2026-41940 immediately. On any host that was internet-exposed and unpatched, assume compromise: remove unknown SSH keys from root, sweep for unfamiliar PHP web shells, block the indicator domains wrned[.]com, cp.dene[.]de[.]com, and wpsock[.]com at egress, rotate cPanel and WHM root credentials, and check bash_history for evidence of attacker reconnaissance.

Ivanti EPMM zero-day actively exploited - attackers are getting admin-level RCE on mobile device management servers (CVE-2026-6973)

Ivanti disclosed Wednesday that attackers are exploiting a zero-day in Endpoint Manager Mobile (EPMM) to gain admin-level remote code execution on enterprise MDM servers. CVE-2026-6973. Successful exploitation gives the attacker control over the MDM platform that pushes apps and configurations to managed mobile fleets - a foothold that can pivot into managed devices and the corporate identity layer. CISA added the flaw to its Known Exploited Vulnerabilities catalog the same day with a federal patch deadline next week. Ivanti products have a long history of zero-day exploitation.

Check
Inventory Ivanti EPMM (formerly MobileIron Core) instances and check whether any are internet-reachable. Hunt EPMM admin logs for unusual admin actions, new admin accounts, or unfamiliar OAuth tokens issued since April.
Affected
Ivanti Endpoint Manager Mobile (EPMM) installations on versions before the May 6 patch. Acute risk for internet-reachable EPMM instances. The MDM context means a successful exploit can push tampered apps or profiles to every managed mobile device. Federal agencies under BOD 22-01 must patch by mid-May.
Fix
Upgrade Ivanti EPMM to the patched release per Ivanti's advisory. Restrict EPMM admin access to internal networks or VPN-only paths until patched. Rotate EPMM admin credentials and any API tokens issued for downstream integrations (SCEP, certificate authorities, identity providers). Audit managed mobile devices for unfamiliar configuration profiles or VPN configurations pushed since April.

Palo Alto Networks firewalls have a critical hole that lets attackers run code as root - hackers are already using it, no patch until May 13 (CVE-2026-0300)

Palo Alto Networks confirmed Wednesday that attackers are exploiting a zero-day in its firewall login portal to run code as root on PA-Series and VM-Series firewalls. CVE-2026-0300 (CVSS 9.3) is a buffer overflow in the User-ID Authentication Portal (Captive Portal) that lets unauthenticated attackers send crafted packets and execute code without any login. Palo Alto Unit 42 attributed the activity to CL-STA-1132, a likely state-sponsored cluster that started probing on April 9 and achieved RCE a week later. Attackers deploy tunneling tools and enumerate Active Directory using the firewall's service account. First patches arrive May 13. Shadowserver counts 5,800+ exposed VM-Series firewalls.

Check
Inventory Palo Alto PA-Series and VM-Series firewalls. Check whether the User-ID Authentication Portal is enabled and reachable from untrusted IPs. Hunt nginx crash logs for evidence of clearing since April 9.
Affected
PA-Series and VM-Series firewalls running PAN-OS with the User-ID Authentication Portal exposed to public internet or untrusted IPs. CVE-2026-0300, CVSS 9.3 (8.7 if portal restricted to internal IPs). Prisma Access, Cloud NGFW, and Panorama are NOT affected. Shadowserver tracks 5,800+ exposed VM-Series instances; thousands more likely sit behind load balancers.
Fix
Restrict the User-ID Authentication Portal to trusted internal networks - this is the primary mitigation until patches arrive. Disable the portal entirely if not strictly required. Block ports 6081 and 6082 from untrusted IPs. Stage May 13 patches: 12.1.4-h5, 11.2.7-h13, 11.1.4-h33, 10.2.10-h36. Treat any compromised firewall as a domain-wide breach starting point - rotate firewall service account credentials.

Hackers raced to exploit a critical LiteLLM flaw 36 hours after disclosure - any attacker who could reach the proxy could read all stored AI API keys (CVE-2026-42208)

LiteLLM, the popular open-source gateway used to centralize API access for OpenAI, Anthropic, and other AI providers, has a critical pre-authentication SQL injection bug that attackers started exploiting just 36 hours after the security advisory went public. The flaw lets anyone who can reach the proxy port read all the API keys stored inside - including master keys, virtual keys, and provider credentials. The bug was in the bearer-token check: the token was concatenated into a SQL query instead of passed as a parameter. Sysdig saw the first attack at 04:24 UTC on April 26, hitting three tables that hold the most valuable secrets.

Check
If you run any internet-facing LiteLLM proxy, patch to v1.83.7-stable today and treat every API key, virtual key, and stored provider credential as compromised.
Affected
LiteLLM versions 1.81.16 through 1.83.6, internet-reachable on the default proxy port. CVE-2026-42208, CVSS 9.3, pre-auth SQL injection. Blast radius is closer to a full cloud account compromise than a typical web app bug because LiteLLM holds OpenAI, Anthropic, and AWS Bedrock credentials.
Fix
Patch to LiteLLM v1.83.7-stable. If you can't upgrade, set 'disable_error_logs: true' under 'general_settings' as a workaround. Rotate every virtual key, master key, and upstream provider credential. Audit upstream provider billing for unexpected API calls since April 24. Block traffic from 65.111.27.132 and 65.111.25.67 (AS200373).

Microsoft confirms a Windows Shell flaw that lets attackers spoof anything in File Explorer is being exploited - patch now (CVE-2026-32202)

Microsoft confirmed yesterday that a Windows Shell spoofing flaw, CVE-2026-32202, is being exploited in the wild. The bug lets an attacker craft files that appear in File Explorer with fake names, icons, and paths - so a malicious .exe can show up looking like a benign PDF, leading users to double-click and run it. Microsoft patched the bug in the April 14 Patch Tuesday but only confirmed in-the-wild exploitation on April 28, raising urgency for any environment that hasn't deployed April patches. The flaw is particularly dangerous on shared file servers, USB drops, and email attachments - any path where users trust File Explorer to tell them what's what.

Check
Confirm every Windows endpoint has the April 14 Patch Tuesday update installed, especially any host that opens shared drives, USB drives, or email attachments.
Affected
Windows endpoints without the April 14, 2026 patch installed. CVE-2026-32202 affects all currently supported Windows versions including Windows 10, 11, and Server. Acute risk on hosts that handle external files: receptionists, finance staff opening invoices, IT staff handling user-submitted USB drives, anyone receiving email attachments from outside the organization.
Fix
Deploy the April 14 Patch Tuesday update via your usual patching process, prioritizing user endpoints over servers. Verify deployment with MDM rather than trusting WSUS compliance numbers. Enable 'show file extensions' as a Group Policy default. Re-train staff on file-trust basics this month. Watch for unusual process spawns from explorer.exe.

All cPanel and WHM versions had a critical authentication bypass that attackers may have been exploiting since February - emergency patches now released (CVE-2026-41940)

cPanel disclosed a critical authentication bypass on Monday affecting every cPanel and WHM version - including end-of-life builds. CVSS 9.8. The bug let unauthenticated attackers log in as administrators by abusing how the cPanel session daemon writes session files during login. Hosting providers including Namecheap, KnownHost, hosting.com, HostPapa, and InMotion took cPanel and WHM offline globally for hours while patches deployed. Researchers at watchTowr published a working proof-of-concept on April 29. KnownHost reports possible targeted exploitation as early as February 23, 2026 - more than two months before disclosure.

Check
If you run any cPanel or WHM server, confirm it's patched to 11.110.0.97, 11.118.0.63, 11.126.0.54, 11.132.0.29, 11.134.0.20, or 11.136.0.5 today.
Affected
All cPanel and WHM versions before the April 28 emergency patch, plus end-of-life versions. CVE-2026-41940, CVSS 9.8. Successful exploitation grants root-equivalent access on the server, exposing every hosted website, database, email account, and customer data. KnownHost reports possible exploitation since February 23, 2026.
Fix
Run '/scripts/upcp --force' to pull the latest patched cPanel build immediately. Audit authentication logs for unusual successful logins between February 23 and April 28 - any login from an unfamiliar IP during that window may indicate prior compromise. Block cPanel ports (2082-2087, 2095-2096, 2077-2078) at the firewall to non-trusted IP ranges.

CISA adds four more flaws to KEV - SimpleHelp authorization bypass (CVSS 9.9), Samsung MagicINFO, and the D-Link DIR-823X bug already powering fresh Mirai botnets

CISA added four flaws to KEV on April 24 with a May 8 federal deadline. The headline is CVE-2024-57726 (CVSS 9.9), a missing authorization in SimpleHelp RMM that lets a low-privileged technician mint API keys above their role and escalate to server admin; companion CVE-2024-57728 (CVSS 7.2) chains a path traversal for RCE. SimpleHelp featured in DragonForce and Akira ransomware campaigns last year. CVE-2024-7399 (CVSS 8.8) is a Samsung MagicINFO 9 path traversal with a public PoC since 2024. The fourth, CVE-2025-29635, is the D-Link DIR-823X bug we covered last week.

Check
Inventory exposed instances of SimpleHelp, Samsung MagicINFO 9 Server, and any remaining D-Link DIR-823X routers. SimpleHelp is the priority - it sits inside the IT trust boundary.
Affected
SimpleHelp before 5.5.8 against CVE-2024-57726 and CVE-2024-57728 (chained to RCE as the SimpleHelp server user). Samsung MagicINFO 9 Server unpatched against CVE-2024-7399. D-Link DIR-823X firmware 240126 and 24082 against CVE-2025-29635 - the product line is discontinued and no vendor patch exists.
Fix
Upgrade SimpleHelp to 5.5.8+ and rotate every API key issued by every technician account, since unprivileged techs could have minted privileged keys during the vulnerable window. Audit SimpleHelp session logs for anomalies. Patch Samsung MagicINFO and remove its internet exposure. For D-Link DIR-823X, replace the hardware - there is no fix. Treat May 8 as your own deadline.

Over 10,500 Zimbra servers still vulnerable to actively-exploited XSS as CISA gives federal agencies just three days to patch (CVE-2025-48700)

Shadowserver scan data published Friday shows over 10,500 Zimbra Collaboration Suite instances still unpatched against CVE-2025-48700, a Classic-UI XSS that Synacor fixed in June 2025 but CISA only added to KEV on April 20. Exposed servers split nearly evenly between Asia (3,794) and Europe (3,793). The flaw triggers when a victim simply views a crafted email - no clicks - and runs JavaScript inside their authenticated session for mailbox theft and MFA backup-code retrieval. Zimbra is a recurring APT target: Russia's Winter Vivern, APT29, and APT28 have all run Zimbra-XSS campaigns against NATO and Ukrainian targets.

Check
If you run Zimbra anywhere - including subsidiaries, acquired companies, and overseas regional offices - confirm patch status against CVE-2025-48700 today.
Affected
Zimbra Collaboration Suite 8.8.15, 9.0, 10.0, and 10.1 without the June 2025 security patches. Exploitation requires a user to view a crafted email in the Classic UI; servers using only the Modern UI are not exposed via this specific flaw, but related issues are addressed by the same patch. CVSS 6.1.
Fix
Apply the June 2025 patches across all instances. Where immediate patching is impossible, switch users to the Modern UI as a stopgap and remove webmail from direct internet exposure. Audit the past 60 days of mailbox audit logs for unusual TGZ archive creation, MFA backup-code retrieval, application-password generation, and bulk address-book access. Rotate application passwords issued during the vulnerable window.

Federal patch deadline for 13-year-old Apache ActiveMQ flaw is Wednesday - 7,500+ servers still exposed online (CVE-2026-34197)

Federal agencies have until April 30 - this Wednesday - to patch Apache ActiveMQ servers against CVE-2026-34197, a remote code execution flaw that has been hiding in the open source message broker for 13 years. Shadowserver shows more than 7,500 ActiveMQ servers still exposed online and unpatched. The bug normally requires a login, but on ActiveMQ versions 6.0.0 through 6.1.1 a separate older flaw lets attackers skip the login step entirely - making this an unauthenticated remote takeover on those builds. The vulnerability was found using Anthropic's Claude AI assistant by a researcher at Horizon3.ai, who said the discovery was '80% Claude.'

Check
Inventory every Apache ActiveMQ server, including in subsidiary networks and old developer environments, and patch this week before the federal deadline.
Affected
Apache ActiveMQ Classic versions before 5.19.4 and 6.x versions before 6.2.3. CVSS 8.4. ActiveMQ 6.0.0 through 6.1.1 are at acute risk because a separate flaw (CVE-2024-32114) removes the login requirement entirely on those versions, making this an unauthenticated takeover. ActiveMQ Artemis is not affected.
Fix
Upgrade to ActiveMQ Classic 5.19.4 or 6.2.3 (ideally to 5.19.6 or 6.2.5). Change any default admin:admin credentials before exposing the broker again. Hunt broker logs for POSTs to /api/jolokia/ containing 'addNetworkConnector', for unexpected outbound HTTP from the Java process, and for unexpected child processes. Restrict the Jolokia API to internal networks only.

CISA and UK NCSC warn 'FIRESTARTER' backdoor survives Cisco ASA/Firepower patches - US agency compromised, hardware replacement recommended

CISA and the UK's National Cyber Security Centre jointly published a malware analysis report for FIRESTARTER, a persistent backdoor that China-linked group UAT-4356 (the same crew behind 2024's ArcaneDoor campaign) planted on Cisco ASA and Firepower firewall devices by chaining CVE-2025-20333 (VPN web server RCE) and CVE-2025-20362 (unauthorized access). The implant hooks into Cisco's Service Platform mount list, a boot-time configuration that controls which programs run when the device starts, so it survives reboots, firmware upgrades, and the September 2025 patches for those two CVEs. CISA found FIRESTARTER on an already-patched US federal civilian agency's Cisco Firepower device through continuous network monitoring - attackers silently returned in March 2026 to deploy a second-stage implant called Line Viper without needing to re-exploit the original vulnerabilities. Updated Emergency Directive ED 25-03 now orders federal agencies to audit every Cisco ASA and Firepower device they run and submit device memory snapshots for CISA analysis. The stark guidance for everyone else: if you confirm a compromise, replace the hardware. Reimaging is not enough because the bootloader itself may be implanted.

Check
Inventory every Cisco ASA and Firepower Threat Defense device in your environment - including branch offices, remote sites, and lab gear - and check patch status against CVE-2025-20333 and CVE-2025-20362 as the absolute minimum baseline.
Affected
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) devices running ASA/FTD software, particularly any units that were internet-exposed and unpatched between the September 2025 patch release and the date you actually applied it. Devices patched in that window may still carry the FIRESTARTER implant because the backdoor survives patching.
Fix
Patch any ASA/FTD device still vulnerable to CVE-2025-20333 or CVE-2025-20362 immediately. Then perform a core dump on every device following CISA's supplemental direction and look for FIRESTARTER indicators described in MAR AR26-113A and the joint advisory AA26-113A. Any device showing indicators of compromise must be replaced with new hardware - do not trust reimaging or factory reset, because the persistence mechanism modifies the Cisco Service Platform mount list and the bootloader may be affected. Rotate all VPN credentials and admin passwords on affected devices. Hunt for Line Viper and review firewall logs for unexpected outbound connections from management interfaces for the period after initial patching.