Search/CVE-2020-26258
● CVE — Medium

CVE-2020-26258

Vendordebian, fedoraproject, xstream, apacheProductdebian linux, fedora, xstream, strutsDiscoveredDec 16, 2020UpdatedOct 7, 2026

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling. The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist if running Java 15 or higher. No user is affected who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream…

CVSS v3.1
6.3 MEDIUM
EPSS
81.8%
probability of exploitation in 30 days
CISA KEV
Not listed
no confirmed exploitation reported
News coverage
0
sources referencing this CVE
Related IOCs
0
seen in the same coverage
CVSS v3.1 Detail
Attack VectorNETWORK
Attack ComplexityHIGH
Privileges RequiredLOW
User InteractionNONE
ScopeCHANGED
ConfidentialityHIGH
IntegrityNONE
AvailabilityNONE
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
Connections
5 relationships
Timeline
disclosure → media coverage
Dec 16, 2020
Disclosure — published as a CVE record. · last revised by NVD Oct 7, 2026
Public PoC (2)
Unverified third-party code — review before executing.