CVE•Published 2021-08-23•Modified 2026-10-07•1 article on news•5 live references•NVD data

CVE-2021-39141Xstream · Xstream

Vulnerability data via NVD (ingested)

CVSS v3.1

8.5

HIGH

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

EPSS percentile

Exploit Prediction Scoring System · top 3% of all CVEs

Weaknesses (CWE)

CWE-434Unrestricted Upload of File with Dangerous Type CWE-502Deserialization of Untrusted Data

Description

XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability 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. XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose.

Timeline

Published 2021-08-23

Modified 2026-10-07

External references

NVD MITRE Exploit-DB trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag3 hosts

vuln:CVE-2021-39141

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Xstream Xstream"

All exposed Xstream Xstream instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Xstream"

HTTP body or banner mentions "Xstream" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2021-39141