CVE-2017-20239: MDwiki contains a cross-site scripting vulnerability that allows remote attackers to execute arbitrary JavaScr

Routine

MEDIUM 6.1DOWNGRADE

CVE-2017-20239 is a medium-severity flaw (CVSS 6.1) affecting mdwiki. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

MDwiki contains a cross-site scripting vulnerability that allows remote attackers to execute arbitrary JavaScript by injecting malicious code through the location hash parameter. Attackers can craft URLs with JavaScript payloads in the hash fragment that are parsed and rendered without sanitization, causing the injected scripts to execute in the victim's browser context.

Why this priority

Public exploit reference

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	0.3% (top 82%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-04-12
Last modified	2026-06-17

Publisher (CNA): VulnCheck · Vendor: dynalon

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

Am I affected?

Timeline

2026-04-12 13:16 UTCPublished CVE record published
2026-06-17 01:15 UTCUpdated Record last modified

dynalon mdwiki DOWNGRADE

Affected: 0.6.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.6.2

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.6.2 (Debian / Ubuntu)

apt-cache madison mdwiki sudo apt install mdwiki=<VERSION_BEFORE_0.6.2> sudo apt-mark hold mdwiki

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

dnf --showduplicates list mdwiki sudo dnf downgrade mdwiki-<VERSION_BEFORE_0.6.2> sudo dnf versionlock add mdwiki

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-2017-20239?

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

Is CVE-2017-20239 being exploited?

CVE-2017-20239 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-2017-20239 affect?

CVE-2017-20239 affects mdwiki. Severity is medium (CVSS 6.1). MDwiki contains a cross-site scripting vulnerability that allows remote attackers to execute arbitrary JavaScript by injecting malicious code through the location hash parameter. Attackers can craft URLs with JavaScript payloads in the hash

How urgent is CVE-2017-20239?

Priority 31/100. Public exploit reference

References

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