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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2021-39141

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.

HIGH 8.5EPSS 16.1%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 16.1%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.1
8.5 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS
16.12% probability · 97th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-434, CWE-502
Affected
xstream/xstream · debian/debian linux · fedoraproject/fedora · netapp/snapmanager · oracle/business activity monitoring · oracle/commerce guided search · oracle/communications billing and revenue management elastic charging engine · oracle/communications cloud native core automated test suite · oracle/communications cloud native core binding support function · oracle/communications cloud native core policy · oracle/communications unified inventory management · oracle/retail xstore point of service · oracle/utilities framework · oracle/utilities testing accelerator · oracle/webcenter portal
Source
security-advisories@github.com
EPSS trend
0%10%20%3 November 2026: 16.12%3 November 20263 November 2026

EPSS 16.1% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.