CVE•Published 2021-08-23•Modified 2026-10-07•1 article on news•5 live references•NVD data
CVE-2021-39148Xstream · 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
92
Exploit Prediction Scoring System · top 8% of all CVEs
Weaknesses (CWE)
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
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-2021-39148Hosts 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-2021-39148Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2021-39148Censys host search filtered to this CVE id.
grep.app
CVE-2021-39148Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2021-39148GitHub code search for direct mentions.
Google dork
"CVE-2021-39148" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.