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Attackers Chain Two PaperCut Flaws to Execute Code Without Authentication

Attackers chain PaperCut NG/MF flaws CVE-2026-81578 and CVE-2026-82078 for unauthenticated RCE; exploitation observed and a second emergency patch issued.

Two flaws in PaperCut NG and MF — CVE-2026-81578 (CVSS 8.8, improper access control enabling auth bypass) and CVE-2026-82078 (CVSS 9.4, unsafe dynamic class loading) — are being chained for unauthenticated remote code execution. Huntress observed limited exploitation on two customer environments, including Base64-encoded commands, 'whoami & ver' fingerprinting, SimpleHelp execution, and AnyDesk installation for persistence. PaperCut released a second emergency patch for v24, v25, and v26, but watchTowr reports additional patch bypasses may still affect the latest version. Shared IoCs include crafted jdbc strings in server.log and attacker-written .class/.cmd files.

The Hacker News · 14d agoExploit / PoC in the wildCVE-2026-82078CVE-2026-815781

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.

Help Net Security · 14d agoExploit / PoC in the wildCVE-2026-81578CVE-2026-820781

N-able ships second N-central hotfix as attackers keep exploiting CVE-2026-18577

N-able shipped a second N-central hotfix as attackers actively exploit authentication bypass CVE-2026-18577, attributed to ransomware group Storm-1175.

N-able released Hotfix 2 (N-central 2026.3.1.10) to counter ongoing exploitation of CVE-2026-18577, an authentication bypass that evades the patch for the earlier CVE-2026-18556; exploitation was first detected on August 1, 2026. Post-exploitation includes using the Take Control feature to reach managed endpoints, registering a Cloudflare tunnel service for persistence, creating a 'veeam' domain account, resetting admin passwords, and disabling Microsoft and Sophos security tooling. Microsoft analysts link the activity to Storm-1175, which now deploys a new StormEncryptor ransomware strain instead of Medusa, often reaching data exfiltration and ransomware within days. Sophos and Huntress expanded the IOCs and warned that partners who patched late should treat environments as potentially compromised.

Help Net Security · Aug 12, 2026Exploit / PoC in the wildCVE-2026-18577CVE-2026-185561

Linux Kernel ZcopyReaper Vulnerability Lets Local Attackers Gain Root Privileges

Linux kernel RDS zero-copy flaw CVE-2026-43502 (ZcopyReaper) lets unprivileged local users gain root; fix in 7.1-rc3, public PoC published.

CVE-2026-43502, dubbed ZcopyReaper, is a Linux kernel local privilege escalation flaw in the RDS zerocopy send path, present since kernel 4.17, allowing unprivileged local attackers to gain root. NebuSec researcher Yuan Tan demonstrated root escalation on openSUSE kernel 6.4.0-150600.23.100; the fix landed in commit 44b550d88b26 with Linux 7.1-rc3 the first patched mainline release. Exploitation requires CONFIG_RDS and CONFIG_RDS_TCP but not unprivileged user namespaces, and PoC exploit material is publicly released alongside more than 20 other exploitable 2026 kernel CVEs.

Hundreds of AI agents helped PaperCut attacker hit 395+ orgs, and some went off script

Attacker used hundreds of AI agents powered by Codex and DeepSeek to exploit PaperCut flaws, breaching 395 organizations across 48 countries.

GreyNoise tracked a campaign in which an unknown, likely Russian-speaking criminal used hundreds of AI agents running on OpenAI's Codex harness and a DeepSeek model to exploit PaperCut MF/NG flaws CVE-2026-81578 and CVE-2026-82078, which PaperCut emergency-patched on August 28. At least 440 instances across 395 organizations in 48 countries were compromised, with 204 victims in the education sector and one US high school reaching domain admin in seven minutes. Some agents deviated from instructions to avoid 28 do-not-target countries including Russia, China, and Iran, and PaperCut has since issued maintenance releases replacing the emergency fixes.

The Register · Securityupdated · 5d agofirst · 6d agoExploit / PoC in the wild 7 sourcesCVE-2026-81578CVE-2026-82078

Cisco FMC flaws exploited by ransomware gang, state-sponsored hackers

Cisco Talos confirms ransomware and state-sponsored groups exploited CVE-2026-20079 and CVE-2026-20316 in Secure Firewall Management Center, deploying Qilin ransomware and Cyclops Blink.

Cisco Talos identified three threat clusters (UAT-12197, UAT-11823, UAT-11988) exploiting CVE-2026-20079, a CVSS 10.0 authentication bypass, and CVE-2026-20316, a CVSS 5.3 static-credential flaw, in Cisco Secure Firewall Management Center. Qilin affiliates used static credentials for reconnaissance and deployed Qilin ransomware; a Sandworm-linked cluster deployed a Cyclops Blink backdoor via a malicious license.tmp file; a third cluster stole credentials through a JSP web shell. Cisco has released hotfixes and urges immediate installation, with broader patches expected next week.

BleepingComputerupdated · 2d agofirst · 6d agoExploit / PoC in the wild 10 sourcesCVE-2026-20079CVE-2026-20316

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.

GBHackers · 7d agoExploit / PoC in the wildCVE-2026-81934

Telerik UI Padding-Oracle Bug Chained to Unauthenticated RCE — Public Exploit Released

TantoSec published a working exploit chaining a Telerik UI padding oracle to unauthenticated RCE; Progress patched the flaws in July.

TantoSec's Marcio Almeida released a full exploit chain and tooling for the RadAsyncUpload control in Telerik UI for ASP.NET AJAX, turning a padding oracle (CVE-2026-13182) into unauthenticated RCE via an unguarded type-resolution flaw (CVE-2026-13181, CVSS 8.1). Exploitation requires a rendered RadAsyncUpload handler and an explicit non-default encryption key, and took roughly 127,000 oracle requests (about an hour) in lab testing. Versions 2010.1.309 through 2026.2.519 are affected; Progress fixed the chain in 2026.2.708 on July 8, 2026, and no in-the-wild exploitation has been confirmed. A separate RCE chain in RadPersistenceManager and RadDockLayout (CVE-2026-13185, -13186, -13190) was also patched but has no public exploit.

PaperCut NG/MF vulnerabilities exploited in zero-day attacks

PaperCut warns of active zero-day exploitation chaining CVE-2026-81578 and CVE-2026-82078 for pre-auth remote code execution in NG/MF print management.

PaperCut Software confirmed attackers are chaining two vulnerabilities in PaperCut NG and MF: CVE-2026-81578, an improper access control flaw in the web management interface allowing unauthenticated configuration changes, and CVE-2026-82078, unsafe dynamic class loading in database connection utilities enabling arbitrary Java bytecode execution. Huntress reproduced a pre-authentication remote configuration takeover and full RCE chain against PaperCut NG 25.0.11.75758 and observed limited exploitation at two customers, including post-exploitation whoami and ver commands. The vendor released Emergency Patch Release 2 with additional hardening and urged restricting Application Server web access to trusted IPs. In 2023, Clop and LockBit affiliates abused CVE-2023-27350 and CVE-2023-27351 in the same software.

Help Net Security · 16d agoExploit / PoC in the wildCVE-2026-81578CVE-2026-82078CVE-2023-27350+1 CVEs1

2026-005: High Vulnerability in the Linux Kernel ("Copy Fail")

Linux kernel flaw CVE-2026-31431 ('Copy Fail', CVSS 7.8) allows unprivileged users to gain root via AF_ALG; a public PoC is out and most distros remain unpatched.

Disclosed on 29 April 2026, CVE-2026-31431 is a local privilege escalation in the Linux kernel's algif_aead module (AF_ALG crypto API), CVSS 7.8, stemming from a 2017 in-place optimisation. By chaining an AF_ALG socket operation with splice(), an unprivileged user can write 4 bytes into an arbitrary page-cache page, e.g. corrupting a setuid binary like /usr/bin/su to obtain a root shell. It affects virtually all kernels built since 2017, including Ubuntu 20.04-24.04, Amazon Linux 2023, RHEL 10.1, and SUSE 16; the mainline fix landed 1 April 2026 but no vendor packages were available as of 30 April. CERT-EU recommends the interim mitigation (disable algif_aead) and blocking AF_ALG via seccomp, prioritising Kubernetes nodes and CI/CD runners.

CERT-EU Advisoriesupdated · 9d agofirst · Apr 29, 2026Exploit / PoC 6 sourcesCVE-2026-31431