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CVE-2016-7256

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Microsoft Windows. For every flaw being used in attacks, see Exploited flaws; for Microsoft’s, see Microsoft flaws being used in attacks.

CVE-2016-7256 is a security flaw in Microsoft Windows, Microsoft’s operating system for PCs and servers. Attackers can run their own code on Microsoft Windows. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 25 May 2022.[1]

Microsoft Windows is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Microsoft has published a fix or advice.

Description

CISA calls it an open type font remote code execution in Microsoft Windows. In its words: “A remote code execution vulnerability exists when the Windows font library improperly handles specially crafted embedded fonts. An attacker who successfully exploits this vulnerability could take control of the affected system.”[1]

The CVE record adds: “atmfd.dll in the Windows font library in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, and 1607, and Windows Server 2016 allows remote attackers to execute arbitrary code via a crafted web site, aka "Open Type Font Remote Code Execution Vulnerability."”[2]

The underlying weakness is improper access control (CWE-284), in MITRE’s list of common software weaknesses.

It scores 8.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record doesn’t list version ranges for it; Microsoft’s advisory has them[3]. CISA names the product as Microsoft Windows.

Every device with Microsoft Windows needs the update.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 25 May 2022, 2,022 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Jun 2022 to fix it.[1]

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 65%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as not automatable: each attack takes some work.

CISA doesn’t say who was attacked, or how.

Fix

Microsoft has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]

  1. Update Microsoft Windows now.On Windows: Settings, Windows Update, Check for updates, then restart. Office updates come the same way, or from any Office app: File, Account, Update Options. Then turn on automatic updates, so the next fix arrives on its own.
  2. If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 8.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 65%.[4]

See also

Other Microsoft Windows flaws

Other improper access control flaws

  • CVE-2015-3306, ProFTPD: improper access control ·
  • CVE-2026-21962, Oracle HTTP Server and Oracle Weblogic Server Proxy Plug-in: improper access control ·
  • CVE-2026-56290, Joomlack Page Builder: improper access control ·
  • CVE-2026-34908, Ubiquiti UniFi OS: improper access control ·
  • CVE-2026-48907, Widget Factory Joomla Content Editor: improper access control ·

Added the same day

  • CVE-2019-3010, Oracle Solaris: privilege escalation ·
  • CVE-2016-3393, Microsoft Windows: graphics device interface (GDI) remote code execution ·
  • CVE-2016-1010, Adobe Flash Player and AIR: integer overflow ·
  • CVE-2016-0984, Adobe Flash Player and AIR: use-after-free ·
  • CVE-2016-0034, Microsoft Silverlight: runtime remote code execution ·

Every Microsoft flaw on CISA’s list · Everything added in May 2022

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Windows Open Type Font Remote Code Execution Vulnerability”. Known Exploited Vulnerabilities Catalog, added 25 May 2022.
  2. ^ National Institute of Standards and Technology. “CVE-2016-7256 Detail”. National Vulnerability Database, published 10 Nov 2016.
  3. ^ Microsoft. Advisories and fixes: docs.microsoft.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.646, percentile 99.2, 31 Oct 2026.
  5. CVE Program. “CVE-2016-7256”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.