CVE-2021-26264 [Medium] | Security Vulnerability in Deltav Workstation

CVE-2021-26264 is rated Low Risk (27.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.19%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.04%	0.19%	+0.14%
2	2023-03-07	0.89%	0.04%	-0.84%
3	2022-02-04	—	0.89%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.04%

0.19%

+0.14%

2023-03-07

0.89%

0.04%

-0.84%

2022-02-04

—

0.89%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.1	3.1	MEDIUM	`CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.6	4.0	[email protected]
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]
4.9	2.0	MEDIUM	`AV:L/AC:L/Au:N/C:N/I:N/A:C` Click to expand Access vector (AV:L) Requires local access to the target system. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:C) Complete availability impact.	3.9	6.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

6.1

3.1

MEDIUM

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

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.6

4.0

[email protected]

5.5

3.1

MEDIUM

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

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

4.9

2.0

MEDIUM

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

Access vector (AV:L): Requires local access to the target system.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:C): Complete availability impact.

3.9

6.9

[email protected]

Affected software / configurations for CVE-2021-26264

Vendor	Product	Version	Raw CPE
emerson	deltav_workstation	—	cpe:2.3:a:emerson:deltav_workstation:-:::::::*
emerson	deltav_distributed_control_system	—	cpe:2.3:o:emerson:deltav_distributed_control_system:-:::::::*

References for CVE-2021-26264

URL	Tags
https://www.cisa.gov/uscert/ics/advisories/icsa-21-355-04	Mitigation Third Party Advisory US Government Resource

URL

CVE-2021-26264 | Emerson DeltaV Missing Authentication for Critical Function

Exploit prediction scoring system (EPSS) score for CVE-2021-26264

Common vulnerability scoring system (CVSS) metrics for CVE-2021-26264

Weakness enumeration for CVE-2021-26264

Affected software / configurations for CVE-2021-26264

References for CVE-2021-26264