CISA KEV Critical Memory corruption exploit reference

CVE-2014-1776 — Microsoft Internet Explorer Memory Corruption Vulnerability

Use-after-free vulnerability in Microsoft Internet Explorer 6 through 11 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via vectors related to the CMarkup::IsConnectedToPrimaryMarkup function, as exploited in the wild in April 2014. NOTE: this issue originally emphasized VGX.DLL, but Microsoft clarified that "VGX.DLL does not contain the vulnerable code leveraged in this exploit. Disabling VGX.DLL is an exploit-specific workaround that provides an immediate, effective workaround to help block known attacks."

Published Apr 27, 2014 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: microsoft

Urgent

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Jan 28, 2022 ☠ APT3

How the score was calculated

Confirmed exploitation (CISA KEV)+35
Exploited by 1 threat actor(s) (MITRE ATT&CK)+10
EPSS 82.7% (30-day exploitation probability)+15
Technical severity (critical)+10
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Confirmed

CISA KEV, listed Jan 28, 2022

EPSS FIRST

82.68%

ahead of 100% of scored CVEs · Oct 14, 2026

Affects

Microsoft

Internet Explorer

CVSS base

9.8

Critical · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented mitigation — blogs.technet.com (NIST National Vulnerability Database)
Documented mitigation — www.kb.cert.org (NIST National Vulnerability Database)
Documented patch — docs.microsoft.com (NIST National Vulnerability Database)
Documented patch — technet.microsoft.com (NIST National Vulnerability Database)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Jul 28, 2022 — passed 1540 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Microsoft Internet Explorer).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Microsoft	Internet Explorer	version 6version 7version 8version 9version 10version 11	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.8	CVSS 3.1	Critical	3.9	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	GitHub, Inc. via GitHub Security Advisories
9.8	CVSS 3.1	Critical	—	—	CISA-ADP via CVE Program (cve.org) e CISA ADP
10.0	CVSS 2.0	High	10.0	10.0	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 134c704f-9b21-4f2e-91b3-4a467353bcc0)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-416 · Use After Free

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed

Jan 28, 2022

Federal deadline

Jul 28, 2022

passed 1540 day(s) ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Threat actors exploiting this CVE MITRE ATT&CK

According to MITRE ATT&CK.

APT3 G0022

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 82.68%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Hunt retroactively in logs from before Jan 28, 2022 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
Affected products added · microsoft/internet explorer
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
2022
Added to CISA KEV catalog
Jan 27, 2022 · CISA
2014
CVE published
Apr 27, 2014 · microsoft

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

16 on the record

technet.microsoft.com/library/security/2963983
Mitigation, Patch, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-021
Patch, Vendor Advisory, vendor-advisory, x_refsource_MS, NIST National Vulnerability Database
www.kb.cert.org/vuls/id/222929
Mitigation, Third Party Advisory, US Government Resource, third-party-advisory, x_refsource_CERT-VN, NIST National Vulnerability Database
blogs.technet.com/b/srd/archive/2014/04/30/protection-strategies-for-the-security-advis
Broken Link, Mitigation, x_refsource_CONFIRM, NIST National Vulnerability Database
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
www.fireeye.com/blog/uncategorized/2014/04/new-zero-day-exploit-targeting-internet-ex
Broken Link, x_refsource_MISC, NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2014-1776
GitHub Security Advisories
www.vicarius.io/vsociety/posts/cve-2014-1776-use-after-free-vulnerability-in-microsof
Third Party Advisory, NIST National Vulnerability Database
securitytracker.com/id
Broken Link, Third Party Advisory, VDB Entry, vdb-entry, x_refsource_SECTRACK, NIST National Vulnerability Database
github.com/advisories/GHSA-44fv-7jv8-5cpp
GitHub Security Advisories
www.signalsec.com/cve-2014-1776-ie-0day-analysis/
Exploit, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
www.osvdb.org/106311
Broken Link, vdb-entry, x_refsource_OSVDB, NIST National Vulnerability Database
secunia.com/advisories/57908
Broken Link, third-party-advisory, x_refsource_SECUNIA, NIST National Vulnerability Database
www.securityfocus.com/bid/67075
Broken Link, Third Party Advisory, VDB Entry, vdb-entry, x_refsource_BID, NIST National Vulnerability Database
www.signalsec.com/cve-2014-1776-ie-0day-analysis
GitHub Security Advisories
www.vicarius.io/vsociety/posts/cve-2014-1776-use-after-free-vulnerability-in-microsof
Third Party Advisory, NIST National Vulnerability Database

Elsewhere on this site

Microsoft
every CVE for this vendor

2022-01
what else CISA listed that month

Memory corruption
same class

CWE-416
other pages naming this weakness

Related CVEs (same products)

High CVE-2021-27085 Microsoft Internet Explorer Remote Code Execution Vulnerability KEV Mar 11, 2021
High CVE-2021-26411 Microsoft Internet Explorer Memory Corruption Vulnerability KEV Mar 11, 2021
Medium CVE-2020-0878 Microsoft Edge and Internet Explorer Memory Corruption Vulnerability KEV Sep 11, 2020
High CVE-2020-1380 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Aug 17, 2020
High CVE-2020-0968 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Apr 15, 2020
High CVE-2020-0674 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Feb 11, 2020

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2014-1776 is "Microsoft Internet Explorer Memory Corruption Vulnerability", rated Critical. It affects Internet Explorer (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 82.68% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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