Adobe Genuine Service creates a named pipe writable by EVERYONE, served by a process running as SYSTEM. Adobe fixed it in July, published no advisory, and scored it a 4.0.
Spektion Research discovered and disclosed a remotely accessible named pipe vulnerability in Adobe Genuine Service, caught at runtime, where static tools don't look.
This post is part of an ongoing series from Spektion Research documenting vulnerabilities discovered through Spektion's runtime analysis. Read on for the full details on CVE-2026-71381.
AGSService.exe, which runs as SYSTEM. That makes this a lateral movement and privilege escalation primitive rather than the local-only issue the published CVSS vector implies.NullSessionPipes.The Adobe Genuine Software Integrity Service (Genuine Service, or AGS) is a "service that periodically verifies whether Adobe apps on your machine are genuine and notifies you if they are not," according to Adobe. In other words, AGS is the anti-piracy service bundled with Adobe software installations, checking to ensure the installed applications are legitimate.
Because of where and how the application is installed, many Adobe customers likely don't know they're running this service unless they read the EULA, or noticed it before clicking the download button on Adobe's site.
Any current Adobe user is more than likely running this service today, on their own computer or, more importantly, across every machine in their organization.
This vulnerability was identified using Spektion's runtime exposure management platform on an affected endpoint. Spektion monitors software behavior during execution by observing system calls, process creation events, and API activity in real time, rather than scanning files at rest.
When Adobe Genuine Service launched, Spektion flagged that four of its binaries call the named pipe creation API with a security descriptor granting write access to Everyone, with remote clients enabled. Spektion's research team reproduced the pipe creation on a clean install and confirmed which binaries create it. Spektion did not attempt a write from a second host. Because the pipe is created with a mode that accepts remote clients, it is reachable by anyone with access to the host, which follows from the pipe descriptor and Microsoft's documented behavior for that mode.
When an Adobe product is installed, it comes bundled with the Adobe Genuine Service tool. At least four of the included files call CreateNamedPipeW with an EVERYONE_W ACL and a pipe mode of PIPE_ACCEPT_REMOTE_CLIENTS.
This isn't an isolated pattern. For a broader look at how often remotely accessible named pipes show up in production software, see Spektion's research: Using Runtime Monitoring to Detect the Hidden Threat of Remotely Accessible Named Pipes.
Adobe's published assessment of this vulnerability:
AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NSpektion's assessment of this CVE description, CVSS score, attack vector, and CWE:
PIPE_ACCEPT_REMOTE_CLIENTS, the Attack Vector should be Network rather than Local, per Microsoft's own definition of the pipe mode: "Connections from remote clients can be accepted and checked against the security descriptor for the pipe."Spektion's proposed scoring for this CVE:
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NBasis for this scoring:
PIPE_ACCEPT_REMOTE_CLIENTS, so under Microsoft's documented behavior for that mode it is reachable from another host. Spektion confirmed the pipe and its security descriptor on a clean install; it did not attempt a cross-host write.AGSService.exe running as SYSTEM.On the Attack Vector specifically: under the CVSS v3.1 specification, Local means the vulnerable component "is not bound to the network stack" and the attacker's path runs through read, write, or execute capabilities on the target, whether at the console or over a remote shell such as SSH. Adobe's description reuses that language, with SMB as the remote example. In this case, SMB is the transport the named pipe itself listens on once it is created with PIPE_ACCEPT_REMOTE_CLIENTS. An attacker never needs a shell on the target; the pipe server is reachable "at the protocol level one or more network hops away," which is the specification's definition of Network. A named pipe served by a SYSTEM process, reachable from another host, is a lateral movement primitive, and a 4.0 does not tell a defender that.
Even the most up-to-date installers for Creative Cloud and other Adobe applications that bundle this service still ship the old 8.x version. The updated version isn't installed until the Windows Task runs for the first time, a 6-hour delay.
The update mechanism also doesn't appear to work consistently across Adobe applications. In testing, installing Adobe Acrobat Reader as a stand-alone application, instead of through Creative Cloud, did not consistently receive the update.
The CVE record's Solutions field states: "No action is required of Adobe app users to received the fixed version of AGS; it receives automatic updates." (The typo is Adobe's.) That was not Spektion's experience. Given the risks associated with this vulnerability type, Spektion recommends a remediation plan that does not depend on Adobe's automatic update mechanism.
If your environment supports initiating scheduled task mechanisms organization-wide:
Adobe-Genuine-Software-Integrity-Scheduler-1.0 task from within Windows Task Scheduler.If an immediate update isn't possible or realistic in your environment, use available EDR or other on-host methods to audit interaction with the named pipes this application creates for anything suspicious.
Can AGS be removed? Spektion did not test removal. Given the service's role in license validation, and given that Adobe's EULA section 3.4 makes the genuineness check a condition of the license, disabling or removing it can affect installed or purchased Adobe software. Treat removal as a licensing decision, not a routine hardening step.
Any presence of this tool prior to version 10.1.0.33 is vulnerable and should be remediated. These files are located within the following directories:
C:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\C:\Program Files (x86)\Common Files\Adobe\Adobe Desktop Common\AdobeGenuineClient\Fixed version metadata (GC client):
cef8e8d97cf81eec7b0cf337fa282b02ddb0efcdAdobeGCClient.exeC:\Users\gocartbot\Jenkins\workspace\gc-client-next\main@2\build\msvs_win32\Release\x86\build\gcclient-next\AdobeGCClient\AdobeGCClient.pdbUse a tool like pipelist to determine which named pipes exist on a system, along with their ACLs and pipe mode. A device is vulnerable if it has one of the named pipes below with an ACL of EVERYONE_W and a pipe mode of PIPE_ACCEPT_REMOTE_CLIENTS:
adobe_gc_pipe_[0-9]{4,5}_[0-9]{4,5}gc_pipe_[a-z]{5}\s[0-9]The following is example Spektion telemetry observed in production tenants:
{"process_path":"C:\\Program Files (x86)\\Common Files\\Adobe\\AdobeGCClient\\AGSService.exe","outputs":{"acl":"EVERYONE_W","filePath":"\\\\.\\pipe\\adobe_gc_pipe_redacted","lpValueName":"PIPE_ACCEPT_REMOTE_CLIENTS|PIPE_ACCESS_DUPLEX"}}{"process_path":"C:\\Program Files (x86)\\Common Files\\Adobe\\AdobeGCClient\\AGMService.exe","outputs":{"acl":"EVERYONE_W","filePath":"\\\\.\\pipe\\adobe_gc_pipe_redacted","lpValueName":"PIPE_ACCEPT_REMOTE_CLIENTS|PIPE_ACCESS_DUPLEX"}}Present telemetry shows this software running in 60% of Spektion's monitored customer tenants as of August 2026. A tenant counts as affected when AGS binaries appear in either install path and at least one runtime detection has fired on them.
In addition to the named pipe vulnerability, Spektion also observed the following runtime weaknesses related to this software:
C:\Users\Public\Documents\AdobeGC\*adobe_gc_pipe_[0-9]{4,5}_[0-9]{4,5}, gc_pipe_[a-z]{5}\s[0-9]C:\Windows\Temp\AdobeGCLogs (acl: EVERYONE_WRITE), C:\Users\Public\Documents\AdobeGCData (acl: EVERYONE_WRITE){'serviceName': 'Adobe Genuine Software Monitor Service', 'servicePath': 'C:\\Program Files (x86)\\Common Files\\Adobe\\AdobeGCClient\\AGMService.exe', 'serviceShortName': 'AGMService'}adobe_gc_pipe_[0-9]{4,5}_[0-9]{4,5}, gc_pipe_[a-z]{5}\s[0-9]C:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\AdobeGCClient.exe, C:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\AGSService.exe{'commandLine': 'C:\\Program Files (x86)\\Common Files\\Adobe\\AdobeGCClient\\AGSService.exe \\\\.\\pipe\\gc_pipe_redacted', 'currentDirectory': 'C:\\Program Files (x86)\\Common Files\\Adobe\\AdobeGCClient'}{'fullRegPath': '\\REGISTRY\\MACHINE\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run', 'lpData': '"C:\\Program Files (x86)\\Common Files\\Adobe\\AdobeGCClient\\AGCInvokerUtility.exe"', 'lpValueName': 'AdobeGCInvoker-1.0'}C:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\: AdobeGCClient.exe, AGMService.exe, AGCInvokerUtility.exe, AGSService.exeC:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\AGSService.exe, {'flags': '~WINHTTP_FLAG_SECURE', 'server': 'agsupdate.adobe.com', 'url': 'win32/AGC_5_0_0_950_win32_cef.zip', 'port': '80'}. This vulnerability was discovered by the Spektion Research Team while running Spektion and is disclosed in accordance with Spektion's coordinated vulnerability disclosure policy. Spektion thanks its partners at VulnCheck for managing the disclosure process as its CNA.
AGSService.exe named pipe was shared with Adobe.Adobe Genuine Service is the primary integrity and licensing platform Adobe uses to ensure its customers are running legitimate, legally licensed software. Because of where it's installed (Common Files) and the inconsistencies between the application name written to the registry and the file metadata associated with the binaries involved, some traditional VTM solutions might miss this application's presence altogether.
As Spektion continues to work with vendors on responsible disclosure, it is consistently surprised by how often those communications reveal a lack of understanding of how the vendor's own software works, and by how broken the CVE process is overall. Throughout this escalation and CVE issuance, Spektion reached a point where it stopped asking Adobe PSIRT for clarification and relied on its own analysis to reach informed conclusions. Some key items that were lacking or incomplete in those conversations:
All of this reinforces Spektion's view that CVEs, while a meaningful data point, are increasingly unreliable and often published too late.
This finding is a reminder that runtime behavior, what software actually does when it runs, is a fundamentally different attack surface than static analysis or file-based scanning can see. Keeping software updated remains the most reliable defense, and runtime visibility remains the most reliable way to find what static tools miss.
adobe_gc_pipe_[0-9]{4,5}_[0-9]{4,5}gc_pipe_[a-z]{5}\s[0-9]Adobe-Genuine-Software-Integrity-Scheduler-1.0. Action: C:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\AGSService.exe. Run as: SYSTEM. Trigger: every 6 hours, indefinitely, highest privileges.AdobeGCInvokerLogon. Action: C:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\agcinvokerutility.exe. Run as: Everyone. Trigger: at log on of any user.AdobeGCInvoker-1.0. Action: C:\Program Files (x86)\Common Files\Adobe\AdobeGCClient\agcinvokerutility.exe. Run as: Everyone. Trigger: daily.AdobeGCClient.exeAGMService.exeAGCInvokerUtility.exeAGSService.exeAdobeGCMutex_SANullSessionPipes policy)
Many exploitable weaknesses never get a CVE. Book a runtime exposure assessment and Spektion will show what's actually exploitable across your endpoints.