CVE-2020-10688Public exploitNetwork attack vector

Reflected XSS via unencoded exception parameter

Published May 27, 2021 · Updated Aug 4, 2024

Cross-site scripting in Red Hat RESTEasy before 3.11.1.Final and before 4.5.3.Final allows remote attackers to execute script via a query value. StringParameterInjector inserts an unencoded parameter value into the RESTEASY003870 extraction-error message, which an HTML 404 error page renders as markup. Exploitation requires a REST endpoint whose parameter conversion fails and a victim who opens the crafted URL; successful exploitation runs script in that victim's browser.

CVSS severity6.1
Medium
EPSS probability1.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Red Hat RESTEasy before 3.11.1.Final and before 4.5.3.Final allows remote attackers to execute script via a query value. StringParameterInjector inserts an unencoded parameter value into the RESTEASY003870 extraction-error message, which an HTML 404 error page renders as markup. Exploitation requires a REST endpoint whose parameter conversion fails and a victim who opens the crafted URL; successful exploitation runs script in that victim's browser.

The record

CVE
CVE-2020-10688
Published
May 27, 2021
Updated
Aug 4, 2024
Vendor
Red Hat
Product
RESTEasy
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=resteasy 3.11.1.Final, resteasy 4.5.3.Final

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Red Hat · RESTEasyversion=resteasy 3.11.1.Final, resteasy 4.5.3.Final

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.4GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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