CVE-2021-29505

CVE-2021-29505 is a high-severity vulnerability in Xstream with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 78% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-502.

Key facts

Description

XStream is software for serializing Java objects to XML and back again. A vulnerability in XStream versions prior to 1.4.17 may allow a remote attacker has sufficient rights to execute commands of the host only by manipulating the processed input stream. No user who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types is affected. The vulnerability is patched in version 1.4.17.

Frequently asked questions

What is CVE-2021-29505?
XStream is software for serializing Java objects to XML and back again. A vulnerability in XStream versions prior to 1.4.17 may allow a remote attacker has sufficient rights to execute commands of the host only by manipulating the processed input stream. No user who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types is affected. The vulnerability is patched in version 1.4.17.
How severe is CVE-2021-29505?
CVE-2021-29505 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-29505 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 78% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29505?
CVE-2021-29505 primarily affects Xstream. In total, 42 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-29505?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-29505 published?
CVE-2021-29505 was published on 2021-05-28 and last updated on 2026-06-17.

References

Affected products (42)

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