Advisory · CVE-2026-70147
Heap overflow in Microsoft PostScript Printer Driver allows network code execution
The Microsoft PostScript Printer Driver has a heap-based buffer overflow an unauthenticated attacker can trigger over the network to execute code. Microsoft rates it CVSS 3.1 9.8.
- Vendor
- Microsoft
- Product
- Microsoft PostScript Printer Driver
- Identifier / CWE
- CVE-2026-70147
CWE-122 - Action timing
- Immediate
Explain it like I’m five
Print drivers run with deep system trust, and this one can be overflowed by network input before any page comes out.
- 01Reach the component
An unauthenticated attacker sends crafted network traffic to a Windows system running Microsoft PostScript Printer Driver.
- 02Memory flaw triggers
The component mishandles the input and corrupts or reuses memory outside its intended bounds.
- 03Code runs
The attacker gains code execution in the component's context on the target system.
What happened
Microsoft disclosed CVE-2026-70147 in its October 2026 update guide: a heap-based buffer overflow (CWE-122) in the Microsoft PostScript Printer Driver lets an unauthorized attacker execute code over a network.
Microsoft lists the affected Windows releases in its update guide. Apply the October 2026 security updates for your release rather than relying on a version guess here.
What to do
- Inventory every Microsoft PostScript Printer Driver deployment, including test, training, and individually managed instances.
- Apply the vendor fix or upgrade exactly as directed in the linked vendor bulletin or advisory.
- Restrict network access to Microsoft PostScript Printer Driver while remediation is underway, especially for internet-facing instances.
- Review application and server logs for spooler crashes, unusual print jobs from unfamiliar hosts, and print servers restarting outside maintenance.
- Check for accounts, content, or configuration created outside normal change processes, and rotate exposed credentials where access cannot be ruled out.
- Verify the deployed version or patch level after remediation.
Management note
Print infrastructure keeps being a soft, privileged target. Patch print servers with the rest of the critical set and limit who can reach them.