CVE-2020-5274Network attack vector

Information disclosure via unescaped exception rendering

Published Mar 30, 2020 · Updated Aug 4, 2024

Information disclosure in Symfony 4.0.0 through 4.4.4 and 5.0.0 through 5.0.4 allows remote authenticated users to expose exception data. The ErrorHandler exception template writes exception class, message, and trace-function values into HTML without escaping, and it renders stack traces when debug mode is disabled. Exploitation requires an application path that raises an attacker-influenced exception and a user to view the resulting error page, exposing trace data and injected markup.

CVSS severity4.6
Medium
EPSS probability1.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Information disclosure in Symfony 4.0.0 through 4.4.4 and 5.0.0 through 5.0.4 allows remote authenticated users to expose exception data. The ErrorHandler exception template writes exception class, message, and trace-function values into HTML without escaping, and it renders stack traces when debug mode is disabled. Exploitation requires an application path that raises an attacker-influenced exception and a user to view the resulting error page, exposing trace data and injected markup.

The record

CVE
CVE-2020-5274
Published
Mar 30, 2020
Updated
Aug 4, 2024
Vendor
Symfony
Product
Symfony
Classifications
CWE-209, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 30, 2020CVE 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=>= 4.0.0, < 4.4.5
  2. Affected versionversion=>= 5.0.0, < 5.0.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Symfony · Symfonyversion=>= 4.0.0, < 4.4.5; version=>= 5.0.0, < 5.0.5

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
4.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
5.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-209Generation of Error Message Containing Sensitive Information
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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