CVE-2020-28847: Cross Site Scripting (XSS) vulnerability in xCss Valine v1.4.14 via the nick parameter to /classes/Comment.

Routine

MEDIUM 5.4DOWNGRADE

CVE-2020-28847 is a medium-severity flaw (CVSS 5.4) affecting valine. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross Site Scripting (XSS) vulnerability in xCss Valine v1.4.14 via the nick parameter to /classes/Comment.

Why this priority

No elevated risk signals yet

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

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 59%)
CISA exploited list	No
Weakness	CWE-79
Published	2022-04-05
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: valine.js

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

Am I affected?

Timeline

2022-04-05 16:15 UTCPublished CVE record published
2026-06-17 03:10 UTCUpdated Record last modified

valine.js valine DOWNGRADE

Affected: 1.4.14

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4.14

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.4.14 (Debian / Ubuntu)

apt-cache madison valine sudo apt install valine=<VERSION_BEFORE_1.4.14> sudo apt-mark hold valine

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

dnf --showduplicates list valine sudo dnf downgrade valine-<VERSION_BEFORE_1.4.14> sudo dnf versionlock add valine

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-2020-28847?

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

Is CVE-2020-28847 being exploited?

CVE-2020-28847 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-2020-28847 affect?

CVE-2020-28847 affects valine. Severity is medium (CVSS 5.4). Cross Site Scripting (XSS) vulnerability in xCss Valine v1.4.14 via the nick parameter to /classes/Comment.

How urgent is CVE-2020-28847?

Priority 29/100. No elevated risk signals yet.

Related CVEs

CVE-2022-38545 CRITICAL 9.6 DOWNGRADE Valine v1.4.18 was discovered to contain a remote code execution (RCE) vulnerability which allows attackers to
CVE-2021-34801 MEDIUM 5.3 DOWNGRADE Valine 1.4.14 allows remote attackers to cause a denial of service (application outage) by supplying a ua (aka

References

← Back to latest CVEs