CVE-2019-18636: A cross-site scripting (XSS) vulnerability in Jitbit .NET Forum (aka ASP.NET forum) 8.3.8 allows remote attack

Routine

MEDIUM 5.4DOWNGRADE

CVE-2019-18636 is a medium-severity flaw (CVSS 5.4) affecting .net forum. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A cross-site scripting (XSS) vulnerability in Jitbit .NET Forum (aka ASP.NET forum) 8.3.8 allows remote attackers to inject arbitrary web script or HTML via the gravatar URL parameter.

Why this priority

Public exploit reference

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	0.6% (top 49%)
CISA exploited list	No
Weakness	CWE-79
Published	2019-11-01
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: jitbit

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

Am I affected?

Timeline

2019-11-01 12:15 UTCPublished CVE record published
2026-06-17 02:25 UTCUpdated Record last modified

jitbit .net forum DOWNGRADE

Affected: 8.3.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.3.8

1. Check installed version

apt-cache policy .net-forum || rpm -q .net-forum || .net-forum --version

2. No fixed release: DOWNGRADE to a release before 8.3.8 (Debian / Ubuntu)

apt-cache madison .net-forum sudo apt install .net-forum=<VERSION_BEFORE_8.3.8> sudo apt-mark hold .net-forum

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

dnf --showduplicates list .net-forum sudo dnf downgrade .net-forum-<VERSION_BEFORE_8.3.8> sudo dnf versionlock add .net-forum

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-2019-18636?

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

Is CVE-2019-18636 being exploited?

CVE-2019-18636 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-2019-18636 affect?

CVE-2019-18636 affects .net forum. Severity is medium (CVSS 5.4). A cross-site scripting (XSS) vulnerability in Jitbit .NET Forum (aka ASP.NET forum) 8.3.8 allows remote attackers to inject arbitrary web script or HTML via the gravatar URL parameter.

How urgent is CVE-2019-18636?

Priority 37/100. Public exploit reference

Software pages

.NET vulnerabilities

References

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