CVE-2021-23388: The package forms before 1.2.1, from 1.3.0 and before 1.3.2 are vulnerable to Regular Expression Denial of Ser

Q: How do I fix CVE-2021-23388?

forms: upgrade to 1.2.1, 1.3.2. Exact commands for each OS are on this page.

Q: Is CVE-2021-23388 being exploited?

CVE-2021-23388 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-2021-23388 affect?

CVE-2021-23388 affects forms. Severity is medium (CVSS 5.3). The package forms before 1.2.1, from 1.3.0 and before 1.3.2 are vulnerable to Regular Expression Denial of Service (ReDoS) via email validation.

Q: How urgent is CVE-2021-23388?

Priority 43/100. Remotely exploitable, no login, no user action

This month

MEDIUM 5.3REMOTEUPGRADE

CVE-2021-23388 is a medium-severity flaw (CVSS 5.3) affecting forms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The package forms before 1.2.1, from 1.3.0 and before 1.3.2 are vulnerable to Regular Expression Denial of Service (ReDoS) via email validation.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 24%)
CISA exploited list	No
Published	2021-06-01
Last modified	2026-06-17

Publisher (CNA): Snyk · Vendor: forms project

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

Am I affected?

Timeline

2021-06-01 14:15 UTCPublished CVE record published
2026-06-17 03:38 UTCUpdated Record last modified

forms project forms UPGRADE

Affected: < 1.2.1 · >= 1.3.0 and < 1.3.2

Fixed in: 1.2.1, 1.3.2

Safe to downgrade to: a release before 1.3.0

1. Check installed version

npm ls forms

2. UPGRADE to 1.2.1

npm install forms@">=1.2.1"

3. If no update is available yet, DOWNGRADE to a release before 1.3.0

npm view forms versions npm install forms@"<1.3.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2021-23388?

forms: upgrade to 1.2.1, 1.3.2. Exact commands for each OS are on this page.

Is CVE-2021-23388 being exploited?

CVE-2021-23388 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-2021-23388 affect?

CVE-2021-23388 affects forms. Severity is medium (CVSS 5.3). The package forms before 1.2.1, from 1.3.0 and before 1.3.2 are vulnerable to Regular Expression Denial of Service (ReDoS) via email validation.

How urgent is CVE-2021-23388?

Priority 43/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-56291 CRITICAL 9.8 EXPLOITED UPGRADE Balbooa Forms Unrestricted Upload of File with Dangerous Type Vulnerability
CVE-2026-101112 MEDIUM 5.3 UPGRADE Joomla Extension - balbooa.com - Unauthorized Deletion of Attachments in Balbooa Forms < 2.4.3.4 - The public
CVE-2026-102425 CRITICAL 10.0 UPGRADE Joomla Extension - balbooa.com - Unauthenticated RCE via field shortcode injection in Balbooa Forms < 2.4.3.4
CVE-2026-102424 HIGH 7.5 UPGRADE Joomla Extension - balbooa.com - Unauthenticated path traversal exfiltrates local files through auto-reply att
CVE-2026-101127 CRITICAL 9.4 UPGRADE Joomla Extension - balbooa.com - Unauthenticated upload filename stored XSS in Balbooa Forms < 2.4.3.4 - The p

References

← Back to latest CVEs