CVE-2021-29505
A public proof of concept exists; no exploitation attested.
- Published2021-05-28
- WeaknessCWE-502 · CWE-94
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
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.
Timeline
dates in UTC- 2021-05-2821:15CVE publishedNVD
- 2026-10-2319:23First public proof of conceptPoC-in-GitHub
- 2026-10-2319:23EPSS crossed 10 %FIRST EPSS
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-29505?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-29505?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 7.3 | = 7.3.4 | no fix published | NVD |
| 7.3 | = 7.3.5 | no fix published | NVD |
| 7.4 | = 7.4.0 | no fix published | NVD |
| 7.4 | = 7.4.1 | no fix published | NVD |
| 7.4 | = 7.4.2 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 16.0 | = 16.0.6 | no fix published | NVD |
| 17.0 | = 17.0.4 | no fix published | NVD |
| 18.0 | = 18.0.3 | no fix published | NVD |
| 19.0 | = 19.0.2 | no fix published | NVD |
| 20.0 | = 20.0.1 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 9.0 | = 9.0 | no fix published | NVD |
| 10.0 | = 10.0 | no fix published | NVD |
| 11.0 | = 11.0 | no fix published | NVD |
14 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
Advisories and patches
- github.comPatch
- www.oracle.comPatch
- www.oracle.comPatch
Detection
read 2026-10-23 19:23 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- 2 repositories, unverifiedMyBlackManba/CVE-2021-29505cuijiung/xstream-CVE-2021-29505 PoC-in-GitHub
Sources
- CISA-ADPSSVC decisionnone2026-10-07
- OpenCVESSVC decisionnone—
- CNACVSS 3.17.5read 2026-10-23
- NVDCVSS 3.18.8read 2026-10-23
- NVDCVSS 2.06.5read 2026-10-23
- CNAweakness (CWE)CWE-502, CWE-94read 2026-10-23
- NVDweakness (CWE)CWE-502read 2026-10-23
- FIRST EPSSEPSS score77.2 %read 2026-10-23
- PoC-in-GitHubproof of concept2read 2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Published
- 2021-05-28
- Last Modified
- 2026-10-07
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-29505?
Is CVE-2021-29505 actively exploited?
What is the CVSS score for CVE-2021-29505?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.