CVE-2014-4123 [Exploited] | Microsoft Internet Explorer

CVE-2014-4123 is rated Critical Active Threat (99.6/100): CVSS High severity, with high exploitation likelihood (EPSS 57.24%, 98th percentile). CISA KEV confirms active exploitation (added 2022-05-25) affecting Microsoft / Internet Explorer. Unauthenticated remote administrative access may be possible. EPSS rose +6.61% over the last day, indicating growing attacker interest. The CISA remediation deadline has passed—treat as an emergency patch priority.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-31	50.63%	57.24%	+6.61%
2	2026-04-22	53.62%	50.63%	-2.99%
3	2026-03-10	—	53.62%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-31

50.63%

57.24%

+6.61%

2026-04-22

53.62%

50.63%

-2.99%

2026-03-10

—

53.62%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
8.8	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.8	5.9	[email protected]
8.8	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.8	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0
6.8	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	8.6	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

8.8

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.8

5.9

[email protected]

8.8

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.8

5.9

134c704f-9b21-4f2e-91b3-4a467353bcc0

6.8

2.0

MEDIUM

AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

8.6

6.4

[email protected]

Affected software / configurations for CVE-2014-4123

Vendor	Product	Version	Raw CPE
microsoft	internet_explorer	7	cpe:2.3:a:microsoft:internet_explorer:7:::::::*
microsoft	internet_explorer	8	cpe:2.3:a:microsoft:internet_explorer:8:::::::*
microsoft	internet_explorer	9	cpe:2.3:a:microsoft:internet_explorer:9:::::::*
microsoft	internet_explorer	10	cpe:2.3:a:microsoft:internet_explorer:10:::::::*
microsoft	internet_explorer	11	cpe:2.3:a:microsoft:internet_explorer:11:::::::*

References for CVE-2014-4123

URL	Tags
http://blogs.technet.com/b/srd/archive/2014/10/14/accessing-risk-for-the-october-2014-security-updates.aspx	Not Applicable Vendor Advisory
http://secunia.com/advisories/60968	Broken Link
http://www.securityfocus.com/bid/70326	Broken Link Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1031018	Broken Link Third Party Advisory VDB Entry
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-056	Patch Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2014-4123	US Government Resource

URL

CVE-2014-4123

CISA KEV Record for CVE-2014-4123

Exploit prediction scoring system (EPSS) score for CVE-2014-4123

Common vulnerability scoring system (CVSS) metrics for CVE-2014-4123

Weakness enumeration for CVE-2014-4123

Affected software / configurations for CVE-2014-4123

References for CVE-2014-4123