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ZDI-26-674: Adobe Acrobat Reader DC Annotation Out-Of-Bounds Write Remote Code Execution Vulnerability

ZDI disclosed CVE-2026-81981, an out-of-bounds write in Adobe Acrobat Reader DC annotation handling that permits remote code execution.

Zero Day Initiative advisory ZDI-26-674 details an out-of-bounds write in the annotation handling of Adobe Acrobat Reader DC. Successful exploitation allows arbitrary code execution after the victim opens a malicious file or visits a malicious page. The advisory carries a CVSS score of 7.8. No exploitation is reported.

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.

Linux kernel LPEs: ZcopyReaper (CVE-2026-43502) and 20 more

Researchers disclosed CVE-2026-43502 (ZcopyReaper), a Linux kernel local privilege escalation in the RDS zerocopy send path, fixed in v7.1-rc3.

Yuan Tan reported a Linux kernel local privilege escalation in the RDS zerocopy send path, tracked as CVE-2026-43502 and dubbed ZcopyReaper, posted to oss-security. The flaw was introduced in Linux v4.17 and fixed by commit 44b550d88b26, first appearing in mainline v7.1-rc3. The researchers demonstrated local privilege escalation on an openSUSE system running kernel 6.4.0-150600.23.100. The post also references 20 additional Linux kernel LPEs, though CVE ids were not provided in the excerpt.

oss-security · 8d agoVulnerabilityCVE-2026-43502

Testing race conditions with memory access tracing and stack-based delay injection

Google Project Zero released MAccConc, Linux kernel tooling that traces memory accesses to explore and test race condition interleavings.

A Google Project Zero researcher published MAccConc (Memory Access Concurrency), tooling for exploring possible interleavings of multithreaded test cases in the Linux kernel, available on GitHub. The tools use KCOV with ASAN outline-mode instrumentation to record per-access memory traces, enabling automatic testing of all A-B-A interleavings plus terminal and GUI explorers for manual analysis. The work targets confirming race condition candidates, building reliable regression tests, and enabling concurrency fuzzing, drawing on ideas from SKI and Ned Williamson's sockfuzzer.

Google Project Zero · 8d agoResearch1

New ZcopyReaper Linux Kernel Vulnerability Enables Privilege Escalation Attacks

ZcopyReaper (CVE-2026-43502) lets unprivileged local attackers reach root on Linux via an RDS zero-copy cleanup flaw dating to kernel 4.17.

CVE-2026-43502 is a lifetime-management error in rds_message_purge() that mishandles zero-copy sends before socket attachment, corrupting kernel memory and enabling local privilege escalation without capabilities or user namespaces. NebuSec demonstrated the exploit on openSUSE kernel 6.4.0-150600.23.100; vulnerable systems need CONFIG_INET, CONFIG_AIO, CONFIG_RDS, and CONFIG_RDS_TCP. The fix landed in mainline commit 44b550d88b26 (Linux 7.1-rc3) with backports to Ubuntu 7.0.0, 6.8.0, and 5.15.0 kernels and multiple Debian branches. NebuSec also released public exploits for 20 additional Linux kernel vulnerabilities in its CyberMeowfia repository.

Re: Retrospective by 'gpg.fail' authors

GPG exploitation talk author clarifies a format-string 0day enabling code execution via printf %n writes and a polyglot PEM certificate payload.

Lexi Groves, author of the gpg.fail talk, clarified on oss-security that the first finding was an actual zero-day: a classic printf injection using %n for memory writes, with multiple X.509 certificates in one PEM file to re-enter and defeat ASLR before calling execv@plt. The payload executed the certificate itself, a polyglot file made by inserting a shebang and bash command into the PEM. A second finding was hash-collided by another party before the author could exploit it.

oss-securityupdated · 6h agofirst · 22h agoResearch 8 sources

PaperCut Zero-Day: Active Exploitation and Pre-Auth RCE

PaperCut NG/MF hit by a pre-auth RCE zero-day under active exploitation; Huntress reproduced the chain and urged immediate patching.

Huntress reports active exploitation of a zero-day in PaperCut NG and PaperCut MF, and says it reproduced a pre-authentication remote code execution chain. The flaw allows unauthenticated attackers to execute code on exposed PaperCut servers. Huntress published urgent patching, exposure-reduction, and detection guidance. No CVE identifier was provided in the announcement.

Huntress · 19d agoExploit / PoC in the wild

Zero-Day Flaw in TP-Link Cameras Enables Eavesdropping

OPSWAT disclosed two zero-days in TP-Link Tapo C200 cameras: CVE-2026-15315 authentication replay bypass enabling surveillance and CVE-2026-15316 denial-of-service, both patched in firmware.

OPSWAT found two zero-days in the TP-Link Tapo C200 camera, widely used for baby/pet monitoring and SOHO security: CVE-2026-15315, an authentication bypass via replay granting administrative access without the password, and CVE-2026-15316, an unauthenticated denial-of-service that crashes the camera's HTTPS service via oversized encrypted credentials. Both were fixed in firmware version V5_1.4.6 released August 18. A third, still-unpatched zero-day rated critical could allow full camera compromise for use as a network foothold; details await an available fix.

Infosecurity Magazineupdated · 10h agofirst · 13h agoVulnerability 3 sourcesCVE-2026-15315CVE-2026-15316

PaperCut Zero-Day Exploited in Attacks, Affecting All NG and MF Versions

PaperCut warns of actively exploited zero-day RCE chain CVE-2026-81578 and CVE-2026-82078 affecting all PaperCut NG and MF versions.

PaperCut alerted customers that attackers are actively exploiting a zero-day affecting all versions of PaperCut NG and MF print management software, with confirmed customer incidents and an ongoing investigation. Emergency patches were released for v25 and v26, and the flaw was later identified as an exploitation chain of CVE-2026-81578 and CVE-2026-82078 enabling remote code execution. Shared IoCs include suspicious post-exploitation activity from pc-app.exe and missing, truncated or deleted server.log files with specific database errors. Users with internet-exposed PaperCut Application Servers are urged to immediately restrict access to trusted IPs; in 2023, CVE-2023-27350 (CVSS 9.8) in the same products was exploited by Lace Tempest to deliver Cl0p and LockBit ransomware.

ZDI-26-583: Clam AntiVirus 7z Archive Parsing Integer Overflow Remote Code Execution Vulnerability

Zero Day Initiative discloses CVE-2026-20215, an integer overflow in ClamAV's 7z archive parsing enabling remote code execution, rated CVSS 8.4.

The Zero Day Initiative published ZDI-26-583 for an integer overflow in Clam AntiVirus's 7z archive parsing. A remote attacker can execute arbitrary code when the antivirus processes a crafted archive, with attack vectors varying by implementation. The flaw is tracked as CVE-2026-20215 and rated CVSS 8.4. The advisory does not mention active exploitation.

ZDI Published Advisories · Aug 13, 2026VulnerabilityCVE-2026-202151

PaperCut Zero-Day Under Active Attack: Emergency Patch Released

PaperCut warns that a zero-day in NG and MF print management products is being actively exploited, shipping emergency patches with no CVE assigned yet.

PaperCut Software confirmed active exploitation of a zero-day affecting PaperCut NG and MF, with confirmed customer incidents, and released emergency patches on Friday ahead of technical details or a CVE assignment. The company urges customers to restrict web access to trusted IP addresses, disconnect application servers from the internet, and watch for indicators including tampered or truncated server.log files, database error strings, and suspicious activity involving pc-app.exe. The article recalls the May 2023 exploitation of CVE-2023-27350 and CVE-2023-27351 by the financially motivated Lace Tempest group, a Clop ransomware RaaS affiliate, though no attacker attribution has been given for the current campaign.

Security Affairs · 18d agoExploit / PoC in the wildCVE-2023-27350CVE-2023-273511

ZDI-26-587: Ashlar-Vellum Cobalt VS File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability

ZDI advisory ZDI-26-587 details a heap-based buffer overflow RCE (CVE-2026-19781, CVSS 7.8) in Ashlar-Vellum Cobalt VS file parsing, requiring user interaction.

The Zero Day Initiative released advisory ZDI-26-587 covering a heap-based buffer overflow in Ashlar-Vellum Cobalt's VS file parsing. A remote attacker can execute arbitrary code when the target opens a malicious file or visits a crafted page. ZDI rated the vulnerability CVSS 7.8 and assigned CVE-2026-19781.

Print management outfit PaperCut is under 0-day attack, and it’s drawing customers’ blood

PaperCut print management software is under active zero-day attack, with only an unofficial emergency patch or server shutdown available as mitigation.

Attackers are actively exploiting an unpatched zero-day vulnerability in PaperCut print management software. The only available fix is an unvalidated, unofficial emergency patch, or taking affected servers offline. PaperCut is widely deployed in enterprise environments, giving exposed instances a broad and consequential attack surface.

The Register · Security · 19d agoExploit / PoC in the wild

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

Privacy Failure in Split-LLM Training, The Returned Gradient Nullifies the Decoys

Researchers show split-LLM training leaks privacy via zero-valued gradients on decoy rows, exposing which activations are real despite passing forward-channel checks.

A systems-security case study of a two-node split-LLM training setup found that the returned output gradient from an Untrusted Cloud Node is exactly zero for decoy rows, revealing which rows are real. Across nine seeds, zero patterns identified real rows in 4,096 of 4,096 frames per run, and an attack on frame contents recovered 0.65 to 1.50 percentage points of extra tokens over a baseline. Both datasets passed forward-channel privacy and quality checks but failed once the returned gradient was included. Row-wise gradient clipping and noise closed the leak for roughly 0.01 nats of held-out cross-entropy, though five unmeasured attack classes remain.

Re: Linux kernel LPEs: ZcopyReaper (CVE-2026-43502) and 20 more

Linux kernel developers discuss a batch of 21 local privilege escalation CVEs, including ZcopyReaper (CVE-2026-43502) in the RDS networking driver.

An oss-security thread examines newly published Linux kernel local privilege escalation issues tracked in the kernel.org security vulnerabilities git repository. CVE-2026-43502, dubbed ZcopyReaper, affects the net/rds (Reliable Datagram Sockets) subsystem. The discussion references roughly 20 additional kernel LPE CVEs published in the 2026 Q3 window.

oss-security · 8d agoVulnerabilityCVE-2026-43502

Serial Microsoft 0-day hunter drops yet another Defender exploit

Researcher Nightmare Eclipse released ShieldCrash, a Microsoft Defender zero-day PoC that bypasses September patches and reads files as SYSTEM.

Zero-day researcher Nightmare Eclipse (MSNightmare) published ShieldCrash, their 11th Microsoft zero-day, a proof-of-concept bypass of the ShieldBreak patch (CVE-2026-69414), which itself had bypassed the fix for RoguePlanet (CVE-2026-50656). ShieldCrash works on Windows 10, Windows 11, and Windows Server systems that have applied the September 2026 patches and allows arbitrary file reads as SYSTEM, though not arbitrary writes or a full SYSTEM shell. Microsoft has not said when it plans to patch the issue. The researcher recently also released zero-days affecting CrowdStrike Falcon (FalconFlank), Kaspersky endpoint antivirus (HardBreacher, patched), and Gen Digital's Avast (PrettyPrague).

Researcher Publishes CrowdStrike Privilege Escalation Zero Day

Researcher NightmareEclipse published FalconFlank, a zero-day local privilege escalation in CrowdStrike Falcon Sensor abusing its Office malicious macro remediation feature.

A researcher known as Nightmare Eclipse published details of FalconFlank, a zero-day privilege escalation that abuses the Microsoft Office malicious macro removal feature in CrowdStrike Falcon Sensor, verified working on fully updated Windows 11 25H2 and Windows Server 2025 with Falcon Phase 3 Optimal Protection. CrowdStrike urged customers to disable the Office File Suspicious Macro Removal policy while it investigates, noting customers remain protected via Cloud Anti-malware for Microsoft Office Files; no CVE has been assigned. The same researcher previously released the Exploitarium dump of over 30 PoC exploits, and researcher Kevin Beaumont confirmed FalconFlank works.

Infosecurity Magazine · 9d agoExploit / PoC

Fake CVE-2023

A fake PoC for WinRAR RCE CVE-2023-40477 posted on GitHub actually deploys VenomRAT through a multi-step infection chain targeting researchers.

Four days after Zero Day Initiative publicly disclosed the WinRAR RCE vulnerability CVE-2023-40477 on August 17, 2023, an actor using the alias whalersplonk published a fake proof-of-concept on GitHub. The Python script actually repurposed public PoC code for GeoServer SQL injection CVE-2023-25157 and triggered an infection chain ending in VenomRAT. The README and an accompanying video lured users into running the script; the video drew over 100 plays. Unit 42 assesses the actor was opportunistic, targeting other miscreants adopting new vulnerabilities rather than researchers specifically.

Palo Alto Unit 42 · Aug 17, 2026MalwareCVE-2023-40477CVE-2023-25157

PaperCut NG/MF Critical Zero-Day Exploited in the Wild

PaperCut confirms active exploitation of critical zero-days CVE-2026-81578 and CVE-2026-82078 in PaperCut NG/MF print management software, with confirmed customer incidents.

PaperCut Software issued an urgent advisory on August 27, 2026, confirming it is investigating active exploitation of flaws in PaperCut NG and PaperCut MF and treating the issue as a security emergency. On August 28 the vendor assigned CVE-2026-81578 and CVE-2026-82078 to the two vulnerabilities forming the exploit chain. At initial disclosure, no CVSS score, vulnerability class, authentication requirements, or exploit path details were public. Rapid7 is tracking the issue as an emerging threat.

Rapid7 Blog · 19d agoExploit / PoC in the wildCVE-2026-81578CVE-2026-82078

Zero Day Initiative — CVE-2026-33824: Remote Code Execution in Windows ...

ZDI details CVE-2026-33824, a double-free in Windows IKEv2 fragment reassembly enabling unauthenticated remote code execution as SYSTEM on Windows.

Zero Day Initiative published technical analysis of CVE-2026-33824, a double-free in the Windows IKE Extension (ikeext.dll) caused by improper ownership handling of a heap blob pointer during IKEv2 fragment reassembly in IkeReinjectReassembledPacket(). A remote unauthenticated attacker can send a crafted IKE_SA_INIT message with a Security Realm Vendor ID followed by fragmented IKE_AUTH payloads to trigger the double free. Successful exploitation could yield arbitrary code execution under the IKEEXT service context (SYSTEM). ZDI also provided IDS detection guidance correlating the two-packet sequence on UDP ports 500 and 4500.