CVE-2021-3350: deleteaccount.php in the Delete Account plugin 1.4 for MyBB allows XSS via the deletereason parameter.

Routine

MEDIUM 6.1DOWNGRADE

CVE-2021-3350 is a medium-severity flaw (CVSS 6.1) affecting delete account. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

deleteaccount.php in the Delete Account plugin 1.4 for MyBB allows XSS via the deletereason parameter.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-02-01
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: delete account project

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

Am I affected?

Timeline

2021-02-01 05:15 UTCPublished CVE record published
2026-06-17 04:04 UTCUpdated Record last modified

delete account project delete account DOWNGRADE

Affected: 1.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4

1. Check installed version

apt-cache policy delete-account || rpm -q delete-account || delete-account --version

2. No fixed release: DOWNGRADE to a release before 1.4 (Debian / Ubuntu)

apt-cache madison delete-account sudo apt install delete-account=<VERSION_BEFORE_1.4> sudo apt-mark hold delete-account

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list delete-account sudo dnf downgrade delete-account-<VERSION_BEFORE_1.4> sudo dnf versionlock add delete-account

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-2021-3350?

delete account: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-3350 being exploited?

CVE-2021-3350 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-2021-3350 affect?

CVE-2021-3350 affects delete account. Severity is medium (CVSS 6.1). deleteaccount.php in the Delete Account plugin 1.4 for MyBB allows XSS via the deletereason parameter.

How urgent is CVE-2021-3350?

Priority 35/100. No elevated risk signals yet.

Software pages

PHP vulnerabilities

Related CVEs

CVE-2021-47905 MEDIUM 6.1 DOWNGRADE MyBB Delete Account Plugin 1.4 contains a cross-site scripting vulnerability in the account deletion reason in

References

← Back to latest CVEs