Attackers plant remote access tools on compromised PaperCut servers
Attackers chained two PaperCut NG/MF zero-days for unauthenticated access, installing SimpleHelp and AnyDesk remote access tools on compromised servers.
An ongoing campaign exploits chained zero-days CVE-2026-81578 (improper access control) and CVE-2026-82078 (unsafe dynamic class loading) in internet-facing PaperCut NG and MF Application Servers, enabling authentication bypass and arbitrary Java bytecode execution. Post-compromise activity includes user and domain enumeration, payload download from sendit.sh, and silent installation of SimpleHelp and AnyDesk for redundant remote access; Defused observed CVE-2026-81578/CVE-2026-82078 exploit activity in honeypots since August 29, including data theft via Derby database dumps. Emergency patches were released August 28 and August 30, but 47% of roughly 2,500 PaperCut installs tracked by Huntress run v23 or older, for which no patch is available.
Exploits in the Wild for Citrix ADC and Citrix Gateway Directory Traversal Vulnerability CVE-2019
Unit 42 confirmed in-the-wild exploitation of CVE-2019-19781, a critical Citrix ADC/Gateway directory traversal flaw enabling unauthenticated file access and RCE.
CVE-2019-19781, a CVSS 9.8 directory traversal vulnerability, affects all supported versions of Citrix ADC and Citrix Gateway. Unit 42 captured multiple exploitation attempts in the wild and identified scanning activity from roughly 700 Shodan-exposed hosts. The flaw stems from improper pathname handling in Apache, allowing unauthenticated attackers to read sensitive files like smb.conf or achieve remote code execution via crafted XML. Palo Alto Networks released Threat Prevention signatures 57497 and 57570 on January 7, 2020, while Citrix published advisories CTX267027 and CTX267679 with responder policy mitigations pending a late-January patch.
Massive Redis Cryptojacking Campaign Hijacks Thousands of Linux Servers
RedisRaider cryptojacking campaign compromises thousands of exposed, unauthenticated Linux Redis servers using cron persistence to deploy XMRig Monero miners.
Hunt.io researchers track a large-scale cryptojacking operation named RedisRaider that scans IPv4 ranges for Redis services exposed on TCP port 6379 and targets instances accepting unauthenticated connections. From a master list of 12,966 candidate hosts, 2,342 were confirmed to accept commands without authentication. Attackers abuse Redis commands (CONFIG SET dir/dbfilename, SET, BGSAVE) to write malicious cron entries into /etc/cron.d or /var/spool/cron, launching XMRig-based Monero miners, with branches including SSH authorized-key injection, Lua probing, and WordPress spraying. The article also references CVE-2026-81934, a Redis TLS use-after-free allowing unauthenticated command execution, fixed in releases including 8.2.9, 8.4.6, 8.6.6, 8.8.2, and 8.10.1.
CISA Adds Exploited MikroTik RouterOS Flaws to Security Alert
CISA added two actively exploited MikroTik RouterOS flaws, CVE-2026-67277 and CVE-2026-86060, to its KEV catalog with a September 13 mitigation deadline.
CISA added CVE-2026-67277 and CVE-2026-86060 in MikroTik RouterOS to the Known Exploited Vulnerabilities catalog on September 10, giving federal agencies until September 13 to apply vendor mitigations. CVE-2026-67277 is a missing-authentication flaw (CWE-306) in the bandwidth-test (btest) service that can expose kernel memory and cause denial of service; CVE-2026-86060 (CWE-88) lets attackers manipulate the trusted RouterOS policy mask for privilege escalation. CISA designated CVE-2026-86060 as requiring forensic triage under Binding Operational Directive 26-04, meaning organizations should hunt for compromise indicators, not just patch. Compromised routers could have altered routing rules, persistence, traffic interception, or use as pivots into internal networks.
Hackers exploit new MikroTik RouterOS flaws to hijack routers
Attackers actively exploit a MikroTik RouterOS SSH authentication bypass and privilege escalation chain, dubbed MikroTrick, to fully hijack internet-exposed routers.
Poland's CERT, with help from GPT-5.5-cyber and GPT-5.6-sol, discovered and confirmed active exploitation of a MikroTik RouterOS chain dubbed MikroTrick: SSH authentication bypass CVE-2026-67276 (incomplete RSA public key validation) chained with privilege escalation CVE-2026-86060 (crafted usernames granting full administrative privileges). A third flaw, CVE-2026-67277, allows unauthenticated kernel memory leaks or router crashes via the bandwidth-test service. Fixes shipped September 3 in RouterOS 7.25beta3, 7.24.2, 7.23.4, and 6.49.21, adding a startup compromise-detection mechanism. Shadowserver data showed 122,500 MikroTik devices with exposed SSH interfaces as of September 5, and the CERT published IoCs including two attacker IP addresses.
Cisco confirms CVE-2026-20079 Secure FMC flaw exploited in attacks
Cisco confirmed active exploitation of CVE-2026-20079, a CVSS 10.0 authentication bypass enabling unauthenticated root command execution in Secure FMC; CISA added it to KEV.
Cisco confirmed in August 2026 that CVE-2026-20079 (CVSS 10.0), an unauthenticated authentication bypass in Secure Firewall Management Center, is being actively exploited, allowing remote attackers to execute scripts and commands as root via crafted HTTP requests to the web interface. CISA added the flaw to its Known Exploited Vulnerabilities catalog, ordering federal civilian agencies to patch by September 12, 2026. Shared IOCs, identical hot fixes, and a July 23 log entry suggest CVE-2026-20079 was used alongside the separately exploited static-credential flaw CVE-2026-20316 in the same attacks. Cisco released patches and cloud fixes, warns hot fixes do not remediate already-compromised devices, and says there are no workarounds.
CISA Adds Six Exploited Flaws to KEV, Including NetScaler, Linux, and SQL Server Bugs
CISA added six actively exploited flaws to KEV, led by Citrix NetScaler CVE-2026-8452, with federal patch deadlines set.
CISA added six flaws to the KEV catalog on August 27, 2026, citing evidence of active exploitation, led by CVE-2026-8452, an improper buffer restriction in Citrix NetScaler ADC and Gateway that can cause denial-of-service. Defused Cyber and Previdian reported active exploitation of CVE-2026-8452, with 36 attempts over 12 days from 12 attacker IPs deploying web shells x.php and z.php. The other additions cover SQL Server RCE (CVE-2019-1068), Linux kernel out-of-bounds write (CVE-2022-0995), Red Hat ABRT and libuser privilege escalations (CVE-2015-5287, CVE-2015-3246), and AjaxPro deserialization RCE (CVE-2021-23758). FCEB agencies must patch CVE-2019-1068 and CVE-2026-8452 by August 29, 2026, and the rest by September 9, 2026.