CVE-2020-35852: Chatbox is affected by cross-site scripting (XSS)

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MEDIUM 6.1DOWNGRADE

CVE-2020-35852 is a medium-severity flaw (CVSS 6.1) affecting chatbox. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Chatbox is affected by cross-site scripting (XSS). An attacker has to upload any XSS payload with SVG, XML file in Chatbox. There is no restriction on file upload in Chatbox which leads to stored XSS.

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	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-02-23
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: getgist

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

Am I affected?

Timeline

2021-02-23 01:15 UTCPublished CVE record published
2026-06-17 03:14 UTCUpdated Record last modified

getgist chatbox DOWNGRADE

Affected: 1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.0 (Debian / Ubuntu)

apt-cache madison chatbox sudo apt install chatbox=<VERSION_BEFORE_1.0> sudo apt-mark hold chatbox

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

dnf --showduplicates list chatbox sudo dnf downgrade chatbox-<VERSION_BEFORE_1.0> sudo dnf versionlock add chatbox

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-2020-35852?

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

Is CVE-2020-35852 being exploited?

CVE-2020-35852 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-2020-35852 affect?

CVE-2020-35852 affects chatbox. Severity is medium (CVSS 6.1). Chatbox is affected by cross-site scripting (XSS). An attacker has to upload any XSS payload with SVG, XML file in Chatbox. There is no restriction on file upload in Chatbox which leads to stored XSS.

How urgent is CVE-2020-35852?

Priority 43/100. Public exploit reference

References

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