All news with #active exploitation tag

🔒 CISA published a malware analysis on FIRESTARTER, a backdoor that enables remote access and persistent control of Cisco Firepower and Secure Firewall devices running ASA or FTD software. The report, co-sealed with NCSC-UK, attributes exploitation to an APT using CVE-2025-20333 and CVE-2025-20362. CISA issued Emergency Directive 25-03 requiring FCEB agencies to identify affected devices, collect forensic data, apply vendor updates, and report findings to mitigate ongoing risk.

🔒 CISA has ordered federal agencies to urgently patch a high-severity Microsoft Defender privilege escalation vulnerability tracked as CVE-2026-33825 and publicly dubbed BlueHammer, after evidence of active exploitation. Microsoft released a patch on April 14 following public disclosure and proof-of-concept code published by a researcher using the handle 'Chaotic Eclipse', who also revealed related Defender issues. Huntress Labs reported attacks showing hands‑on‑keyboard activity and suspicious FortiGate SSL VPN access tied to a Russia‑geolocated IP. Agencies must apply mitigations or update systems within two weeks, with a compliance deadline of May 7.

🔒 A new Mirai-based campaign is actively exploiting CVE-2025-29635, a command-injection RCE that affects D-Link DIR-823X routers, to enlist devices into a botnet. Akamai's SIRT observed the activity in March 2026 and found attackers downloading and executing a shell script that installs a multi-architecture Mirai variant called tuxnokill. The affected DIR-823X line reached end of life in November 2024 and is unlikely to receive a vendor patch. Users are advised to replace EoL devices, disable remote administration, change default passwords, and monitor for configuration changes.

⚠️ Forescout Research Vedere Labs disclosed 22 vulnerabilities, labeled BRIDGE:BREAK, in popular Lantronix and Silex serial-to-IP converters that bridge legacy serial equipment to IP networks. Researchers located nearly 20,000 exposed devices online and warned that several flaws permit full takeover or tampering with serial traffic. Affected models include Lantronix EDS3000PS/EDS5000 and Silex SD330-AC; vendors have issued firmware updates and advisories. Operators should patch immediately, remove default credentials, segment networks, and avoid exposing these converters to the internet.

⚠️ CISA has flagged an information-disclosure vulnerability in Catalyst SD-WAN Manager (CVE-2026-20133) as actively exploited and gave federal agencies four days to secure affected systems. Cisco released patches in late February, stating the flaw is caused by insufficient file system access restrictions that can allow unauthenticated API access to sensitive OS information. CISA added the issue to its Known Exploited Vulnerabilities Catalog on April 20 and directed agencies to follow Emergency Directive 26-03 and Cisco hardening guidance or discontinue affected cloud services if mitigations are unavailable.

🔐 Shadowserver reported that over 6,400 publicly exposed Apache ActiveMQ servers are vulnerable to an actively exploited code injection bug tracked as CVE-2026-34197. The flaw, discovered by Horizon3 researcher Naveen Sunkavally with the help of the Claude AI assistant after 13 years, permits authenticated actors to execute arbitrary code. Apache issued patches on March 30 in ActiveMQ Classic 6.2.3 and 5.19.4, and CISA has warned of in-the-wild exploitation and ordered federal agencies to secure affected systems.

⚠️ CISA added eight vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, citing evidence of active exploitation and highlighting three flaws in Cisco Catalyst SD-WAN Manager. The list includes high-impact issues such as CVE-2025-32975 (Quest KACE SMA, CVSS 10.0) and authentication, path traversal, and XSS flaws in PaperCut, TeamCity, Kentico, and Zimbra. CISA noted prior ties of CVE-2023-27351 to Lace Tempest and recent Arctic Wolf telemetry on KACE abuse; Cisco confirmed active exploitation of two SD-WAN flaws in March 2026. Federal civilian agencies are urged to remediate the three Cisco vulnerabilities by April 23, 2026, and the remaining flaws by May 4, 2026.

⚠️Fortinet researchers observed a campaign exploiting a command injection flaw (CVE-2024-3721) in TBK DVR systems to deploy a Mirai-based, multi-architecture botnet called Nexcorium. Attackers deliver a downloader via crafted HTTP requests that retrieves ARM, MIPS and x86-64 payloads and executes them with elevated privileges. The malware leverages an XOR-encoded configuration, embedded credential lists for brute-force access and multiple persistence mechanisms, and network traffic includes a custom HTTP header referencing Nexus Team that may indicate the actor.

⚠️ CISA added eight vulnerabilities to the Known Exploited Vulnerabilities (KEV) Catalog after observed active exploitation. The additions include flaws affecting PaperCut NG/MF, JetBrains TeamCity, Kentico Xperience, Quest KACE SMA, Synacor Zimbra, and multiple issues in Cisco Catalyst SD‑WAN Manager. Under BOD 22‑01, Federal Civilian Executive Branch agencies must remediate cataloged CVEs by the prescribed due dates; CISA strongly urges all organizations to prioritize timely remediation as part of routine vulnerability management.

🔒 Huntress warns that threat actors are actively exploiting three recently disclosed Microsoft Defender vulnerabilities — codenamed BlueHammer, RedSun, and UnDefend — to gain elevated privileges and disrupt defenses. Microsoft addressed BlueHammer in this week's Patch Tuesday as CVE-2026-33825, but RedSun and UnDefend remain unpatched and have PoCs observed in the wild. Huntress reported weaponization beginning April 10 for BlueHammer and April 16 for RedSun and UnDefend, and said it isolated affected environments while investigating post-exploitation activity.

🔴 The U.S. Cybersecurity and Infrastructure Security Agency (CISA) warned that a high-severity Apache ActiveMQ flaw, CVE-2026-34197, is being actively exploited in attacks. The bug, present for 13 years, allows authenticated attackers to execute arbitrary code via improper input validation and injection. Apache released patches on March 30 for ActiveMQ Classic 6.2.3 and 5.19.4, and CISA added the CVE to its KEV catalog, ordering federal agencies to patch by April 30.

🔓 Threat actors are actively using proof-of-concept exploit code for three recently disclosed Windows vulnerabilities to elevate privileges or disrupt Microsoft Defender. Researcher "Chaotic Eclipse" (aka "Nightmare-Eclipse") published PoCs for BlueHammer, RedSun, and UnDefend in protest over Microsoft’s handling of disclosure. Huntress Labs has observed exploitation in the wild, with BlueHammer seen since April 10, and Microsoft has patched only BlueHammer (CVE-2026-33825) so far while RedSun and UnDefend remain unaddressed.

⚠️ CISA has added CVE-2026-34197 to its Known Exploited Vulnerabilities catalog after active exploitation reports targeting Apache ActiveMQ Classic. The flaw is an improper input validation issue that can enable code injection via the Jolokia management API, potentially allowing arbitrary OS command execution. While the bug typically requires credentials, default credentials and a prior authentication bypass in some versions can render it effectively unauthenticated. Users should upgrade to ActiveMQ 5.19.4 or 6.2.3 to remediate the issue.

🔎 Unit 42 observed automated scans targeting CVE-2023-33538 in several end-of-life TP‑Link routers (TL‑WR940N, TL‑WR740N, TL‑WR841N). Payloads resembled Mirai-like botnet binaries and attempted to download and execute an arm7 ELF, but in-the-wild attempts were flawed and generally failed. Emulation and reverse engineering confirmed a real command-injection flaw in the ssid1 parameter that reaches a system shell, but successful exploitation requires web authentication (default credentials like admin:admin remain a practical risk). TP‑Link lists the devices as EOL with no patches; Unit 42 recommends replacing affected units and avoiding default credentials while using layered protections.

⚠️ A proof-of-concept for a second Microsoft Defender zero-day, dubbed RedSun, was published by researcher 'Chaotic Eclipse', demonstrating a local privilege escalation that grants SYSTEM privileges on patched Windows 10, Windows 11, and supported Windows Server releases when Defender is enabled. The PoC exploits Defender's handling of cloud-tagged files via the Cloud Files API to overwrite system binaries and achieve code execution as SYSTEM. Security analyst Will Dormann of Tharros confirmed the exploit works; some antivirus products detect elements of the PoC due to an embedded EICAR test file. The researcher says the publication was a protest over interactions with the Microsoft Security Response Center.

⚠️Researchers observed attackers exploiting a critical Marimo remote code execution flaw (CVE-2026-39987) to deploy a new NKAbuse variant hosted on Hugging Face Spaces. Attack activity began within hours of public disclosure, with a Space named "vsccode-modetx" serving a dropper script and a malicious binary labeled kagent. The dropper retrieves and runs the payload via curl, then installs persistence via systemd, cron, or macOS LaunchAgent, while Spaces' legitimate HTTPS hosting helps evade detection. Operators are urged to upgrade to version 0.23.0 or block the '/terminal/ws' endpoint if upgrades are not possible.

⚠️ CISA added CVE-2026-34197 — an Apache ActiveMQ improper input validation vulnerability — to the KEV Catalog after evidence of active exploitation. The advisory notes this vulnerability type is a frequent attack vector and poses significant risk to the federal enterprise. CISA reminds Federal Civilian Executive Branch agencies to follow BOD 22-01 remediation deadlines and strongly urges all organizations to prioritize timely mitigation.

⚠️ A critical authentication bypass in nginx-ui (CVE-2026-33032) allows unauthenticated attackers to invoke privileged MCP actions via an unprotected /mcp_message endpoint. Exploitation can write, modify, and reload Nginx configuration files, enabling full server takeover from a single request. NGINX issued fixes (starting with 2.3.4, latest secure build 2.3.6) after disclosures; administrators should update and audit exposed instances immediately.

⚠️ Pluto Security has published a full analysis of a critical vulnerability, CVE-2026-33032, in the nginx UI configuration tool that has been actively exploited since March. The flaw, rated CVSS 9.8, is caused by an unauthenticated MCP endpoint (/mcp_message) — dubbed MCPwn — which allows attackers to inject configs and trigger automatic nginx reloads. The vendor recommends applying the 2.3.4 patch released March 15; short-term mitigations include disabling MCP, locking access to trusted IPs, and reviewing logs for suspicious configuration changes.

⚠️ Cisco Talos researchers report that threat actors have abused n8n managed cloud webhooks since October 2025 to deliver malicious payloads and fingerprint devices via email. Attackers embed URLs on the shared *.app.n8n.cloud subdomain so returned HTML executes in recipients' browsers, sometimes prompting a CAPTCHA that triggers JavaScript-initiated downloads. Observed campaigns delivered modified RMM installers for persistence and used invisible tracking pixels to confirm opens, with message volume jumping sharply by March 2026.