XStream vulnerabilities
- XStream has 1 CVE record published between 28 Oct 2023 and 28 Oct 2026, ranking #352 of 420 vendors on this site by that count.
- Of the 1 with a CVSS score, 1 (100%) are rated critical or high; 0 (0% of all) have no CVSS score.
- 1 vulnerability attributed to XStream is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog; the most recent, CVE-2021-39144, was added on 10 Mar 2023.
- It is marked as known to be used in ransomware campaigns.
- For the 1 KEV entry with a published CVE record, the median time from CVE publication to KEV listing is 564 days.
Records are attributed to XStream from the vendor named in the source records. About the data.
CVE records per year
Show data as a table
| Year | CVE records |
|---|---|
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 1 |
| 2020 | 3 |
| 2021 | 26 |
| 2022 | 4 |
| 2023 | 0 |
| 2024 | 1 |
| 2025 | 0 |
| 2026 | 0 |
2026 is partial (through 28 Oct 2026), shown in a lighter bar.
| Year | Records | Critical | High | Critical or high | Not scored |
|---|---|---|---|---|---|
| 2026 | 0 | 0 | 0 | — | — |
| 2025 | 0 | 0 | 0 | — | — |
| 2024 | 1 | 0 | 1 | 100% | 0% |
| 2023 | 0 | 0 | 0 | — | — |
| 2022 | 4 | 0 | 2 | 50% | 0% |
| 2021 | 26 | 0 | 15 | 57.7% | 0% |
| 2020 | 3 | 0 | 1 | 33.3% | 0% |
| 2019 | 1 | 0 | 1 | 100% | 0% |
| 2018 | 0 | 0 | 0 | — | — |
| 2017 | 0 | 0 | 0 | — | — |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Exploited vulnerabilities in CISA's KEV catalog
| CVE | Product | Name | Added | Ransomware |
|---|---|---|---|---|
| CVE-2021-39144 | XStream | XStream Remote Code Execution Vulnerability | 2023-03-10 | Unknown |
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.27, as of 27 Oct 2026. About the data.
Highest exploit-prediction scores (EPSS)
EPSS estimates the probability that a vulnerability is exploited in the next 30 days. These are the 10 highest-scoring XStream records today.
| CVE | EPSS | Percentile | Severity | In KEV |
|---|---|---|---|---|
| CVE-2021-39144 | 98.1% | 99.9% | High | Yes |
| CVE-2019-10173 | 95% | 99.9% | High | No |
| CVE-2020-26217 | 82.7% | 99.7% | High | No |
| CVE-2020-26259 | 82.4% | 99.7% | Medium | No |
| CVE-2021-21351 | 82.1% | 99.7% | Medium | No |
| CVE-2020-26258 | 81.8% | 99.6% | Medium | No |
| CVE-2021-21341 | 77.8% | 99.6% | High | No |
| CVE-2021-29505 | 77.2% | 99.6% | High | No |
| CVE-2021-21346 | 76.4% | 99.5% | Medium | No |
| CVE-2021-21344 | 76% | 99.5% | Medium | No |
Source: FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.27, as of 27 Oct 2026. About the data.