`\n2. Visit a"}},{"@type":"Question","name":"How severe is CVE-2021-27908?","acceptedAnswer":{"@type":"Answer","text":"CVE-2021-27908 has a CVSS score of 4.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance."}},{"@type":"Question","name":"Which packages are affected by CVE-2021-27908?","acceptedAnswer":{"@type":"Answer","text":"CVE-2021-27908 affects the following packages: mautic/core (Packagist). Ecosystems affected: Packagist."}},{"@type":"Question","name":"How do I fix CVE-2021-27908?","acceptedAnswer":{"@type":"Answer","text":"Update mautic/core to 3.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-27908 is resolved across your whole dependency graph."}},{"@type":"Question","name":"How do I detect CVE-2021-27908 in my Packagist dependencies?","acceptedAnswer":{"@type":"Answer","text":"Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mautic/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version."}},{"@type":"Question","name":"How do I mitigate CVE-2021-27908 if there is no patch (or I can't update yet)?","acceptedAnswer":{"@type":"Answer","text":"Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them."}},{"@type":"Question","name":"Is CVE-2021-27908 actively exploited in the wild?","acceptedAnswer":{"@type":"Answer","text":"Yes. There are 1 known exploit references for CVE-2021-27908, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization."}},{"@type":"Question","name":"What is the EPSS score for CVE-2021-27908?","acceptedAnswer":{"@type":"Answer","text":"CVE-2021-27908 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 26th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority."}},{"@type":"Question","name":"What type of vulnerability is CVE-2021-27908?","acceptedAnswer":{"@type":"Answer","text":"CVE-2021-27908 is classified as Information Exposure (CWE-200), CWE-74 (CWE-74). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation."}},{"@type":"Question","name":"When was CVE-2021-27908 published, and has it been updated?","acceptedAnswer":{"@type":"Answer","text":"CVE-2021-27908 was published on March 23, 2021 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting."}}]}
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🐘 Packagist
Not in CISA KEV
MEDIUM severity

CVE-2021-27908 — core

MEDIUM

CVE-2021-27908 is a medium-severity (CVSS 4.4) Information Exposure vulnerability in mautic/core. 1 public exploit reference exists, so weaponization risk is real. A fix is available for mautic/core — see the affected versions and patch details below.

Mautic vulnerable to secret data exfiltration via symfony parameters

Also known asGHSA-4hjq-422q-4vpx
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs26th percentile — riskier than 26% of all scored CVEsHighest risk
0.00%0.28%0.56%0.84%0.1%0.3%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-27908 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected
🐘mautic/core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Symfony parameters (which is what Mautic transforms configuration parameters into) can be used within other Symfony parameters by design. However, this also means that an admin who is normally not privy to certain parameters, such as database credentials, could expose them by leveraging any of the free text fields in Mautic’s configuration that are used in publicly facing parts of the application.

For example,

  1. Go to Configuration page -> Landing Page Settings -> Analytics script and enter this: <script> console.log("db password is: %mautic.db_password%"); </script>
  2. Visit any landing page and open the JS dev console. You will see the following message with real instance db password: db password is: <real password>

Risk rating: ModerateCVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:L

Patches

Upgrade to 3.3.2

Workarounds

No

References

No

For more information

If you have any questions or comments about this advisory:

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistmautic/coreall versions3.3.2composer require mautic/core:^3.3.2

Affected Products

1 product · 1 configurations
Application
mauticacquia
< 3.3.2
range
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

In all versions prior to Mautic 3.3.2, secret parameters such as databas…

github.comNVDMar 2021

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mautic/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update mautic/core to 3.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-27908 is resolved across your whole dependency graph.

  3. Workarounds

    Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.

Frequently Asked Questions

### Impact Symfony parameters (which is what Mautic transforms configuration parameters into) can be used within other Symfony parameters by design. However, this also means that an admin who is normally not privy to certain parameters, such as database credentials, could expose them by leveraging any of the free text fields in Mautic’s configuration that are used in publicly facing parts of the application. For example, 1. Go to Configuration page -> Landing Page Settings -> Analytics script and enter this: <`script> console.log("db password is: %mautic.db_password%"); </script>` 2. Visit a
O3 Security · Impact-Aware SCA

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CVE-2021-27908: core — Fixed in 3.3.2