CVE-2021-34637: The Post Index WordPress plugin is vulnerable to Cross-Site Request Forgery via the OptionsPage function found

Q: How do I fix CVE-2021-34637?

post index: upgrade to newer than 0.7.5. Exact commands for each OS are on this page.

Q: Is CVE-2021-34637 being exploited?

CVE-2021-34637 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-34637 affect?

CVE-2021-34637 affects post index. Severity is high (CVSS 8.8). The Post Index WordPress plugin is vulnerable to Cross-Site Request Forgery via the OptionsPage function found in the ~/php/settings.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.7.5.

Q: How urgent is CVE-2021-34637?

Priority 49/100. High severity; Public exploit reference

This month

HIGH 8.8UPGRADE

CVE-2021-34637 is a high-severity flaw (CVSS 8.8) affecting post index. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Post Index WordPress plugin is vulnerable to Cross-Site Request Forgery via the OptionsPage function found in the ~/php/settings.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.7.5.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-352
Published	2021-08-02
Last modified	2026-06-17

Publisher (CNA): Wordfence · Vendor: post index project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-08-02 21:15 UTCPublished CVE record published
2026-06-17 03:56 UTCUpdated Record last modified

post index project post index UPGRADE

Affected: <= 0.7.5

Fixed in: newer than 0.7.5

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy post-index || rpm -q post-index || post-index --version

2. UPGRADE to newer than 0.7.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade post-index

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade post-index

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-34637?

post index: upgrade to newer than 0.7.5. Exact commands for each OS are on this page.

Is CVE-2021-34637 being exploited?

CVE-2021-34637 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-34637 affect?

CVE-2021-34637 affects post index. Severity is high (CVSS 8.8). The Post Index WordPress plugin is vulnerable to Cross-Site Request Forgery via the OptionsPage function found in the ~/php/settings.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.7.5.

How urgent is CVE-2021-34637?

Priority 49/100. High severity; Public exploit reference

Software pages

WordPress vulnerabilities · PHP vulnerabilities

References

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