Vulnerability · CVE-2021-25033
noptin noptin URL Redirection to Untrusted Site ('Open Redirect')
Published Feb 14, 2022 · catalog updated Oct 9, 2026 · noptin noptin URL Redirection
Patch now
CVE-2021-25033 is in the CISA known-exploited catalog. Confirm noptin noptin URL Redirection against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (noptin noptin URL Redirection).
- Severity
- Medium6.1
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 2.30%
- Remediation
- Remediation guidance
- Affected products
- cpe noptin/noptin · vendor noptin noptin
The WordPress Newsletter Plugin WordPress plugin before 1.6.5 does not validate the to parameter before redirecting the user to its given value, leading to an open redirect issue
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe noptin/noptin< 1.6.5
- vendor noptin noptinversion unspecified
How to fix CVE-2021-25033
Recommended remediation
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2021-25033 is in the CISA known-exploited catalog. Confirm noptin noptin URL Redirection against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with < 1.6.5. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
What should an analyst verify?
CWE-601: URL Redirection to Untrusted Site (Open Redirect). EPSS 2.30%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 9, 2026 · VulnCheck KEV
Detected
The WordPress Newsletter Plugin WordPress plugin before 1.6.5 does not validate the to parameter before redirecting the user to its given value, leading to an open redirect issue
Oct 9, 2026 · CISA KEV
Known exploited
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Sources
- CVE.orgVulnerability recordCVE-2021-25033
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2021-25033
30-day exploitation probability 2.30%
first.org - NIST NVDVulnerability recordCVE-2021-25033
The WordPress Newsletter Plugin WordPress plugin before 1.6.5 does not validate the to parameter before redirecting the user to its given value, leading to an open redirect issue
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2021-25033
The WordPress Newsletter Plugin WordPress plugin before 1.6.5 does not validate the to parameter before redirecting the user to its given value, leading to an open redirect issue
vulncheck.com
References
Freshness
Last verified in this catalog Oct 24, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.