9.8

CVE-2021-21344: apache activemq

CVSS: 9.8v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2021-21344DEBIAN-CVE-2021-21344CGA-fcpc-9wf9-hv86
Published 22-03-2021Last modified 07-10-2026

Vulnerability summary

CVE-2021-21344 is a critical (CVSS 9.8) vulnerability in apache activemq. EPSS estimates a 75.98% chance of exploitation in the next 30 days, higher than 99.5% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
75.98%
0%100%
Critical · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 10 · Related 7

Timeline

  1. 22-03-2021
    PublishedVulnerability first disclosed.
  2. 07-10-2026
    Last modifiedVulnerability information updated.

Description

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability which may allow a remote attacker to load and execute arbitrary code from a remote host only by manipulating the processed input stream. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.

CVSS metrics

7 scores · 6 sources · 2 versions

EPSS trend

Probability

75.98%

Chance of exploitation in the next 30 days

Percentile

100%

Versus all other CVEs

30-day change

0.00 pp

From 75.98% on 18-09-2026

18-09-202618-10-2026
EPSS score
75.98%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (x-stream.github.io)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Oracle10 products
Apache2 products
Chainguard2 products
  • hadoop-fips-3.3.6All versions (No fix recorded)
  • hadoop-fips-3.4.2All versions (No fix recorded)
Debian2 products
Com.thoughtworks.xstream1 product
  • xstream< 1.4.16
Fedoraproject1 product
Netapp1 product
Ubuntu1 product
  • libxstream-java< 1.4.7-1ubuntu0.1+esm2 | < 1.4.8-1ubuntu0.1+esm3 | < 1.4.11.1-1~18.04.2 | < 1.4.11.1-1ubuntu0.2
X-stream1 product
Xstream1 product

10 vendors · 22 products

References

28 links
Show all 28 references