NVD / CVE Program· CNA apache

CVE-2020-11995: Apache Dubbo default deserialization protocol Hessian2 cause CRE

Noroxi assessment

Priority: Plan (action score 41/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 5.9% (FIRST EPSS); higher than 93.2% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Apache Software Foundation Apache Dubbo 2.7.8.

Add it to your regular patch cycle. Upgrade to Apache Software Foundation Apache Dubbo 2.7.8 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A deserialization vulnerability existed in dubbo 2.7.5 and its earlier versions, which could lead to malicious code execution. Most Dubbo users use Hessian2 as the default serialization/deserialization protool, during Hessian2 deserializing the HashMap object, some functions in the classes stored in HasMap will be executed after a series of program calls, however, those special functions may cause remote command execution. For example, the hashCode() function of the EqualsBean class in rome-1.7.0.jar will cause the remotely load malicious classes and execute malicious code by constructing a malicious request. This issue was fixed in Apache Dubbo 2.6.9 and 2.7.8.

CriticalCVSS 9.8 · v3.1—No exploit Fix available

GHSA-74mg-6xqx-2vrq

Published: Jan 11, 2021
Updated: Jun 16, 2026
EPSS: 5.9% · 93th percentile
CWE: CWE-502

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 2 / 30 · 5.9%

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No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
apache	dubbo	cpe:2.3:a:apache:dubbo

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

apache dubbo2.5.0 and later · up to 2.5.10 inclusive
apache dubbo2.6.0 and later · up to 2.6.8 inclusive
apache dubbo2.7.0 and later · up to 2.7.7 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

Apache Software Foundation Apache Dubbo
- Apache Dubbo and later · before 2.6.9affectedfixed in 2.7.8

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Maven	org.apache.dubbo:dubbo-parent	from 2.7.0 · before 2.7.8	2.7.8
Maven	org.apache.dubbo:dubbo-parent	before 2.6.9	2.6.9

Same product

apache: all records

Other highest-scoring records for the same primary product.

CVE-2021-30181Apache Dubbo RCE on customers via Script route poisoning (Nashorn script injection)
57Plan
CVE-2021-30180Apache Dubbo RCE on customers via Condition route poisoning (Unsafe YAML unmarshaling)
57Plan
CVE-2019-17564Unsafe deserialization occurs within a Dubbo application which has HTTP remoting enabled.
50Plan

Published before and after this one in the same product

← EarlierCVE-2020-1948Jul 14, 2020 · This vulnerability can affect all Dubbo users stay on version 2.7.6 or lower.
44Plan
Later →CVE-2021-25640Jun 1, 2021 · Open Redirect or SSRF vulnerability usage of parseURL
25Monitor
Later →CVE-2021-25641Jun 1, 2021 · Dubbo Zookeeper does not check serialization id
45Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Apache Software Foundation Apache Dubbo	2.7.8	Vendor (CNA)
Maven:org.apache.dubbo:dubbo-parent	2.6.9	Package registry (OSV)
Maven:org.apache.dubbo:dubbo-parent	2.7.8	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

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

nvd-primary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python

1payload = sock.recv(65536)
2job = pickle.loads(payload)

Fixed

python

1payload = sock.recv(65536)
2if not hmac.compare_digest(sign(payload), header_sig):
3    raise PermissionError("invalid signature")
4job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

Object InjectionCAPEC-586likelihood: Medium · High

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

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References

lists.apache.org/thread.html/r5b2df4ef479209dc4ced457b3d58a887763b60b9354c3dc148b2eb5b%40%3Cdev.dubbo.apache.org%3E

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records