CVE-2021-36830 | WordPress Comment Guestbook plugin <= 0.8.0 - Authenticated Stored Cross-Site Scripting (XSS) vulnerability

Authenticated (admin+) Stored Cross-Site Scripting (XSS) vulnerability in Comment Guestbook plugin <= 0.8.0 at WordPress.

Published: 2022-09-30 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36830 is rated Low Risk (30.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.40%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-36830

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.34% 0.40% +0.06%
2 2025-10-06 0.46% 0.34% -0.12%
3 2025-10-01 — 0.46% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36830

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N 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:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.7 2.7 [email protected]
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N 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:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.7 2.7 [email protected]

Weakness enumeration for CVE-2021-36830

Affected software / configurations for CVE-2021-36830

Vendor Product Version Raw CPE
comment_guestbook_project comment_guestbook <= 0.8.0 cpe:2.3:a:comment_guestbook_project:comment_guestbook:*:*:*:*:*:wordpress:*:*

References for CVE-2021-36830

cvelogic Threat Intelligence