CVE-2020-25912: A XML External Entity (XXE) vulnerability was discovered in symphony\lib\toolkit\class.xmlelement.php in Symph

This week

CRITICAL 9.1REMOTEDOWNGRADE

CVE-2020-25912 is a critical-severity flaw (CVSS 9.1) affecting symphony. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A XML External Entity (XXE) vulnerability was discovered in symphony\lib\toolkit\class.xmlelement.php in Symphony 2.7.10 which can lead to an information disclosure or denial of service (DOS).

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.4% (top 28%)
CISA exploited list	No
Weakness	CWE-611
Published	2021-10-31
Last modified	2026-07-09

Publisher (CNA): MITRE · Vendor: getsymphony

Last updated 2026-07-09 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-10-31 19:15 UTCPublished CVE record published
2026-07-09 00:17 UTCUpdated Record last modified

getsymphony symphony DOWNGRADE

Affected: 2.7.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.7.10

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.7.10 (Debian / Ubuntu)

apt-cache madison symphony sudo apt install symphony=<VERSION_BEFORE_2.7.10> sudo apt-mark hold symphony

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

dnf --showduplicates list symphony sudo dnf downgrade symphony-<VERSION_BEFORE_2.7.10> sudo dnf versionlock add symphony

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-2020-25912?

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

Is CVE-2020-25912 being exploited?

CVE-2020-25912 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-2020-25912 affect?

CVE-2020-25912 affects symphony. Severity is critical (CVSS 9.1). A XML External Entity (XXE) vulnerability was discovered in symphony\lib\toolkit\class.xmlelement.php in Symphony 2.7.10 which can lead to an information disclosure or denial of service (DOS).

How urgent is CVE-2020-25912?

Priority 60/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

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References

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