The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization validation via the logged_in_or_has_api_key function in the ~/OMAPI/RestApi.php file that can used to exploit inject malicious web scripts on sites with the plugin installed. This affects versions up to, and including, 2.6.4.
CVE-2021-39341
“—” beside the score: it is equal to NVD's CVSS score.
Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 8.2; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
Update to version 2.6.5, or newer (from the CVE record's solution, Wordfence) — apply it.
- CVSS v3
- 8.2
- EG Score
- 8.2HIGHmedium confidence
- EG Risk
- 68EG Risk 68/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity82% × 45%Impact severity (EG Severity): CVSS 8.2 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: Update to version 2.6.5, or newer (from the CVE record's solution, Wordfence). Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 22%
- EPSS %ILE
- 97th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (8.2): severity, escalated by confirmed exploitation. This CVE's 8.2 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.2 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 22% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-20). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
Update to version 2.6.5, or newer (from the CVE record's solution, Wordfence). Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
November 1, 2021
Last Modified
November 21, 2024
References (3)
- security@wordfence · CVE Programhttps://plugins.trac.wordpress.org/browser/optinmonster/trunk/OMAPI/RestApi.php?rev=2606519#L1460Third Party Advisory
- security@wordfence · CVE Programhttps://wordfence.com/vulnerability-advisories/#CVE-2021-39341Third Party Advisory
- security@wordfence · CVE Programhttps://www.wordfence.com/blog/2021/10/1000000-sites-affected-by-optinmonster-vulnerabilities/Exploit · Third Party Advisory
Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 32× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 92 of 167 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 8 repeat rows among the latest 100 are merged into the row they repeat. The 75 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-23 16:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-22 16:29 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-21 16:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-21 09:07 UTCEG score recompute
- 2026-10-21 09:07 UTCGHSA enrichmentGHSA-whcc-jgf3-q7pm · GitHub severity HIGH · GitHub CVSS 8.2
- 2026-10-20 16:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-19 16:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-18 08:55 UTCEG score recompute
- 2026-10-17 16:29 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-16 16:34 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-15 16:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-14 16:29 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-13 16:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-12 19:11 UTCEG score recompute
- 2026-10-11 23:37 UTCEG score recompute
- 2026-10-11 13:44 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-10 19:56 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-09 20:04 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-10-08 16:40 UTCEPSS rescoreEPSS 22% · 97th percentile
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- 2026-10-02 16:23 UTCEPSS rescoreEPSS 22% · 97th percentile
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- 2026-09-30 15:40 UTCEG score recompute
- 2026-09-30 15:00 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-29 15:15 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-27 13:41 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-26 15:54 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-26 00:21 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-24 14:00 UTCEPSS rescoreEPSS 22% · 97th percentile
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- 2026-09-22 14:44 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-21 20:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-19 15:38 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-18 19:23 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-17 19:23 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-16 14:05 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-15 03:06 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-12 14:57 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-11 14:49 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-11 09:33 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-07 15:58 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-06 13:45 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-05 15:25 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-04 13:57 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-04 05:03 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-09-02 14:09 UTCEPSS rescoreEPSS 22% · 97th percentile
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- 2026-09-01 03:33 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-30 19:14 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-30 01:19 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-28 21:37 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-27 14:22 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-26 14:43 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-25 13:46 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-24 14:13 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-23 00:16 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-21 23:46 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-20 22:52 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-19 17:01 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-18 13:45 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-16 14:53 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-16 02:11 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-15 01:27 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-13 21:57 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-12 13:48 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-11 13:38 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-09 13:44 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-08 16:33 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-07 16:24 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-06 13:44 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-05 19:14 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-02 02:24 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-08-01 04:13 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-07-30 16:25 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-07-30 01:28 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-07-28 15:33 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-07-26 14:52 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-07-25 14:15 UTCEPSS rescoreEPSS 22% · 97th percentile
- 2026-07-24 14:15 UTCEPSS rescoreEPSS 24% · 97th percentile
- 2026-07-23 14:16 UTCEPSS rescoreEPSS 24% · 97th percentile
- 2026-07-23 02:03 UTCEG score recompute
- 2026-07-22 22:50 UTCEG score recompute
- 2026-07-22 14:06 UTCEPSS rescoreEPSS 24% · 97th percentile
- 2026-07-21 15:22 UTCEPSS rescoreEPSS 24% · 97th percentile
- 2026-07-20 17:05 UTCEPSS rescoreEPSS 23% · 97th percentile
- 2026-07-19 14:29 UTCEPSS rescoreEPSS 23% · 97th percentile
- 2026-07-19 02:27 UTCEPSS rescoreEPSS 23% · 97th percentile
- 2026-07-18 10:02 UTCEPSS rescoreEPSS 23% · 97th percentile
- 2026-07-16 17:00 UTCEPSS rescoreEPSS 23% · 97th percentile
Public detection templates
(1 reference)A public Nuclei detection template is referenced for this CVE. A detection template checks whether a system is affected; it is not necessarily exploit code.
- Nucleihttp/cves/2021/CVE-2021-39341.yamlPublished Jun 12, 2025
OptinMonster Plugin < 2.6.5 - Unprotected REST-API
Open source ↗
Related CVEs(same CWE)
Same CWE
10 shownCWE-863 · CWE-285 · CWE-319
Frequently asked(5)
What is CVE-2021-39341?
When was CVE-2021-39341 made public?
Is CVE-2021-39341 actively exploited?
What is the CVSS score of CVE-2021-39341?
How do I remediate CVE-2021-39341?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-39341
Is Your Infrastructure Affected by CVE-2021-39341?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.