CVE-2025-5940: The Osom Blocks – Custom Post Type listing block plugin for WordPress is vulnerable to Stored Cross-Site Scrip

Q: How do I fix CVE-2025-5940?

osom blocks: upgrade to 1.2.2. Exact commands for each OS are on this page.

Q: Is CVE-2025-5940 being exploited?

CVE-2025-5940 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-2025-5940 affect?

CVE-2025-5940 affects osom blocks. Severity is medium (CVSS 6.4). The Osom Blocks – Custom Post Type listing block plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘class_name’ parameter in all versions up to, and including, 1.2.1 due to insufficient input sanitization and output

Q: How urgent is CVE-2025-5940?

Priority 26/100. No elevated risk signals yet.

Routine

MEDIUM 6.4UPGRADE

CVE-2025-5940 is a medium-severity flaw (CVSS 6.4) affecting osom blocks. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Osom Blocks – Custom Post Type listing block plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘class_name’ parameter in all versions up to, and including, 1.2.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 84%)
CISA exploited list	No
Weakness	CWE-79
Published	2025-06-27
Last modified	2026-06-17

Publisher (CNA): Wordfence · Vendor: osompress

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

Am I affected?

Timeline

2025-06-27 08:15 UTCPublished CVE record published
2026-06-17 09:49 UTCUpdated Record last modified

osompress osom blocks UPGRADE

Affected: < 1.2.2

Fixed in: 1.2.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy osom-blocks || rpm -q osom-blocks || osom-blocks --version

2. UPGRADE to 1.2.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade osom-blocks

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade osom-blocks

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-2025-5940?

osom blocks: upgrade to 1.2.2. Exact commands for each OS are on this page.

Is CVE-2025-5940 being exploited?

CVE-2025-5940 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-2025-5940 affect?

CVE-2025-5940 affects osom blocks. Severity is medium (CVSS 6.4). The Osom Blocks – Custom Post Type listing block plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘class_name’ parameter in all versions up to, and including, 1.2.1 due to insufficient input sanitization and output

How urgent is CVE-2025-5940?

Priority 26/100. No elevated risk signals yet.

Software pages

WordPress vulnerabilities

References

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