CVE WatchOct 7, 2026

CVE-2021-21351

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability may allow a

CVSS

5.4

Medium

EPSS

82.1%

p100

KEV

—

Exploit Today

0-100

Published: Mar 23, 2021 · Last modified: Oct 7, 2026 · CWE-434 · CWE-502

EPSS · 30d

82.1%EPSS · 30 days82.1%

2026-09-222026-10-19

Technical 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 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.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-828148.8 HIG

—

———The Duplicator and Duplicator Pro plugins for WordPress are vulnerable to PHP Object Injection in all versions up to, and including, 1.5.17 and 4.6.10, respectively, via deserialization of untrusted database content in DUPX_UpdateEngine::unserializeTest() during migration. This allows unauthenticated attackers to store a serialized object in public site content before an administrator builds a package and later performs a migration or import that runs database search-and-replace. Duplicator Free bundles a Requests 1.7 POP chain that permits attacker-selected callbacks, resulting in direct operating-system command execution. Duplicator Pro bundles an IndexList destructor gadget that permits deletion of an attacker-selected existing file when its containing directory is writable by the installer PHP process; deletion of wp-config.php can expose the setup wizard and lead to site takeover and code execution if the attacker reaches it first and supplies a reachable database they control. The package must be created after the carrier is stored, and a later administrator migration action is required.5h CVE-2026-114198—

—

———Deserialization of untrusted data in Mandiant FLARE floss releases before 3.2.0 allows arbitrary code execution when a crafted .viv or .exe.viv workspace is passed to the floss utility6h CVE-2026-114197—

—

———Deserialization of untrusted data in Mandiant FLARE capa releases before 10.0.0 allows arbitrary code execution when a crafted .viv or .exe.viv workspace is passed to the capa utility6h CVE-2026-878006.8 MED

—

———IBM Cyber Fraud 1.0.0 through 1.0.2 could allow a remote authenticated attacker to execute arbitrary code due to unrestricted upload of a file with a dangerous type.9h CVE-2026-90799—

—

———Unsafe binary deserialisation in chttpd in Apache CouchDB 3.5.2 and below on all platforms allows an authenticated user to cause a denial of service via memory exhaustion. Users are recommended to upgrade to version 3.5.3, which fixes this issue.12h CVE-2026-1133936.3 MED

—

———A vulnerability was determined in DrayTek Vigor2960 1.5.1.6 Revision 8218. This issue affects some unknown processing of the file /cgi-bin/mainfunction.cgi of the component commonupload. Executing a manipulation of the argument upload_path/upload_name can lead to unrestricted upload. The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized. Upgrading to version 1.5.1.7 is capable of addressing this issue. It is advisable to upgrade the affected component. The vendor explains: "2960 1.5.1.7 has corrected many security issues. And 2960 is EoS with limited support, only major issues would be reviewed(e.g. unauthenticated vuln.)". This vulnerability only affects products that are no longer supported by the maintainer.12h