How severe is CVE-2020-7961?

CVE-2020-7961 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-7961?

CVE-2020-7961 affects the following packages: com.liferay.portal:com.liferay.portal.kernel (Maven). Ecosystems affected: Maven.

How do I fix CVE-2020-7961?

Update com.liferay.portal:com.liferay.portal.kernel to 4.35.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7961 is resolved across your whole dependency graph.

How do I detect CVE-2020-7961 in my Maven dependencies?

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

How do I mitigate CVE-2020-7961 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2020-7961 actively exploited in the wild?

Yes. There are 16 known exploit references for CVE-2020-7961, including 1 documented proof-of-concept exploit on Exploit-DB and 10 in-the-wild exploitations 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.

What is the EPSS score for CVE-2020-7961?

CVE-2020-7961 has an EPSS (Exploit Prediction Scoring System) score of 99.9%, placing it in the 100th 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. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2020-7961 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-7961 (Liferay Portal Deserialization of Untrusted Data Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2020-7961?

CVE-2020-7961 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2020-7961?

A Nuclei detection template exists for CVE-2020-7961, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2020-7961 published, and has it been updated?

CVE-2020-7961 was published on March 20, 2020 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

CISA KEV · ACTIVELY EXPLOITED

CRITICAL severity

CVE-2020-7961 — com.liferay.portal.kernel

CRITICAL

CVE-2020-7961 is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in com.liferay.portal:com.liferay.portal.kernel. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) — treat it as actively exploited and patch now. A fix is available for com.liferay.portal:com.liferay.portal.kernel — see the affected versions and patch details below.

Deserialization of Untrusted Data in Liferay Portal

Also known asGHSA-w7pm-cc4v-f3g8

Published

Mar 20, 2020

Updated

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

16 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. Federal agencies were required to remediate by 2022-05-03.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2020-7961.

EPSS Exploitation Probability

via FIRST.org ↗

99.9%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2020-7961 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

☕com.liferay.portal:com.liferay.portal.kernel

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

Description

Deserialization of Untrusted Data in Liferay Portal prior to 7.2.1 CE GA2 allows remote attackers to execute arbitrary code via JSON web services (JSONWS).

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.liferay.portal:com.liferay.portal.kernel`	all versions	4.35.3`com.liferay.portal:com.liferay.portal.kernel:4.35.3`

Affected Products

1 product · 1 configurations

Application

liferay portalliferay

< 7.2.1

range

Exploits & PoCs

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

EDB-48332remotejava✓ Verified

Liferay Portal - Java Unmarshalling via JSONWS RCE (Metasploit)

by Metasploit · Apr 16, 2020

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.liferay.portal:com.liferay.portal.kernel, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.liferay.portal:com.liferay.portal.kernel to 4.35.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7961 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

How to detect CVE-2020-7961

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2020-7961 -u https://target

Template: Liferay Portal Unauthenticated < 7.2.1 CE GA2 - Remote Code Execution
Severity: critical
Impact: Unauthenticated attackers can execute arbitrary code via JSON web services, leading to complete server compromise and access to all portal data.
Remediation: Upgrade Liferay Portal to version 7.2.1 CE GA2 or later to mitigate the vulnerability.

Template by ProjectDiscovery nuclei-templates (dwisiswant0), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

Deserialization of Untrusted Data in Liferay Portal prior to 7.2.1 CE GA2 allows remote attackers to execute arbitrary code via JSON web services (JSONWS).

O3 Security · Impact-Aware SCA

Is CVE-2020-7961 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

9.8/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE Classification

CWE-502Deserialization of Untrusted Data

Weaponization

OpenSSF Scorecard

Package health score

liferay-portal

2.5/10

Maintained10/10

Code-Review0/10

Branch-Protection0/10

Assessed Oct 19, 2026

Timeline

Disclosed

Mar 20, 2020

First exploit

Apr 16, 2020

KEV added

Nov 3, 2021

Last updated

Oct 24, 2026

Identifiers

CVE-2020-7961

GHSA-w7pm-cc4v-f3g8

References

Advisorypacketstormsecurity.com Advisorypacketstormsecurity.com Advisoryportal.liferay.dev Advisoryportal.liferay.dev Advisorynvd.nist.gov Webcisa.gov Webgithub.com Webresearch.checkpoint.com Packagegithub.com Evidenceresearch.checkpoint.com

Related vulnerabilities

Also affects com.liferay.portal.kernel

This CVE is critical severity — higher than any of the other 5 CVEs affecting com.liferay.portal.kernel (highest there: high).

CVE-2025-43792CVE-2025-43793CVE-2025-43770CVE-2025-3526CVE-2024-25607

Same weakness: CWE-502

This CVE is critical severity; 1 of 3 other CVEs with CWE-502 is rated as high or higher (top: critical).

GHSA-673q-mjm6-r5xrCVE-2026-70035CVE-2026-83520Browse all CWE-502

Provenance

Sources

OSV.devNVDCISA KEVFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2020-7961 — com.liferay.portal.kernel

Exploitation Status

Actively exploited in the wild

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

How to detect CVE-2020-7961

Frequently Asked Questions

Is CVE-2020-7961 in your dependencies?