CVE-2021-21348
No exploitation reported by the sources we read.
- Published2021-03-23
- Fixed in5.15.14
- WeaknessCWE-400 · CWE-502
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
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 occupy a thread that consumes maximum CPU time and will never return. 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.
Timeline
dates in UTC- 2021-03-2300:15CVE publishedNVD
- 2026-10-2319:23EPSS crossed 10 %FIRST EPSS
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-21348?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-21348?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD · OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 5.15 | < 5.15.14 | 5.15.14 | NVD · OSV |
| 5.16 | = 5.16.0 | no fix published | NVD |
| 5.16 | = 5.16.1 | no fix published | NVD |
| 5.16 | ≥ 5.16.0, ≤ 5.16.0 | no fix published | OSV |
| 5.16 | ≥ 5.16.1, ≤ 5.16.1 | no fix published | OSV |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 7.3 | = 7.3.2 | no fix published | NVD |
| 7.3 | = 7.3.4 | no fix published | NVD |
| 7.3 | = 7.3.5 | no fix published | NVD |
| 7.4 | = 7.4.0 | no fix published | NVD |
| 7.4 | = 7.4.1 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.4 | = 2.4.0 | no fix published | NVD |
| 2.7 | = 2.7.1 | no fix published | NVD |
| 2.9 | = 2.9.0 | no fix published | NVD |
| 2.12 | = 2.12.0 | no fix published | NVD |
13 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Apache activemq to 5.15.14
Advisories and patches
- x-stream.github.ioRelease Notes
- www.oracle.comPatch · Vendor Advisory
- x-stream.github.ioMitigation
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2021-03-23
- Last Modified
- 2026-10-07
- NVD status
- Analyzed
Frequently asked questions
What is CVE-2021-21348?
Is CVE-2021-21348 actively exploited?
What is the CVSS score for CVE-2021-21348?
Running xstream? Hear about its next vulnerability
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
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Go further
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
- Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.
Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.