CVE-2021-28968: An issue was discovered in PunBB before 1.4.6

Q: How do I fix CVE-2021-28968?

punbb: upgrade to 1.4.6. Exact commands for each OS are on this page.

Q: Is CVE-2021-28968 being exploited?

CVE-2021-28968 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-2021-28968 affect?

CVE-2021-28968 affects punbb. Severity is medium (CVSS 5.4). An issue was discovered in PunBB before 1.4.6. An XSS vulnerability in the [email] BBcode tag allows (with authentication) injecting arbitrary JavaScript into any forum message.

Q: How urgent is CVE-2021-28968?

Priority 30/100. No elevated risk signals yet.

Routine

MEDIUM 5.4UPGRADE

CVE-2021-28968 is a medium-severity flaw (CVSS 5.4) affecting punbb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in PunBB before 1.4.6. An XSS vulnerability in the [email] BBcode tag allows (with authentication) injecting arbitrary JavaScript into any forum message.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-03-22
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: gnu

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

Am I affected?

Timeline

2021-03-22 16:15 UTCPublished CVE record published
2026-06-17 03:47 UTCUpdated Record last modified

gnu punbb UPGRADE

Affected: < 1.4.6

Fixed in: 1.4.6

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy punbb || rpm -q punbb || punbb --version

2. UPGRADE to 1.4.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade punbb

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade punbb

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-2021-28968?

punbb: upgrade to 1.4.6. Exact commands for each OS are on this page.

Is CVE-2021-28968 being exploited?

CVE-2021-28968 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-2021-28968 affect?

CVE-2021-28968 affects punbb. Severity is medium (CVSS 5.4). An issue was discovered in PunBB before 1.4.6. An XSS vulnerability in the [email] BBcode tag allows (with authentication) injecting arbitrary JavaScript into any forum message.

How urgent is CVE-2021-28968?

Priority 30/100. No elevated risk signals yet.

Related CVEs

CVE-2011-3371 MEDIUM 4.3 UPGRADE Multiple cross-site scripting (XSS) vulnerabilities in include/functions.php in PunBB before 1.3.6 allow remot
CVE-2010-0455 MEDIUM 4.3 DOWNGRADE Cross-site scripting (XSS) vulnerability in forum/viewtopic.php in PunBB 1.3 allows remote attackers to inject
CVE-2009-4894 MEDIUM 4.3 UPGRADE Multiple cross-site scripting (XSS) vulnerabilities in profile.php in PunBB before 1.3.4 allow remote attacker
CVE-2008-7241 MEDIUM 6.8 UPGRADE Cross-site request forgery (CSRF) vulnerability in PunBB before 1.2.17 allows remote attackers to hijack the a
CVE-2008-5435 MEDIUM 4.3 UPGRADE Cross-site scripting (XSS) vulnerability in moderate.php in PunBB before 1.3.1 allows remote attackers to inje

References

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