CVE-2020-25864 — consul
MEDIUMCVE-2020-25864 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in github.com/hashicorp/consul. A fix is available for github.com/hashicorp/consul — see the affected versions and patch details below.
HashiCorp Consul Cross-site Scripting vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2020-25864 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/hashicorp/consul🐹github.com/hashicorp/consul🐹github.com/hashicorp/consulReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
HashiCorp Consul and Consul Enterprise up to version 1.9.4 key-value (KV) raw mode was vulnerable to cross-site scripting. Fixed in 1.9.5, 1.8.10 and 1.7.14.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/hashicorp/consul | ≥ 1.9.0&&< 1.9.5 | 1.9.5go get github.com/hashicorp/consul@v1.9.5 |
| 🐹Go | github.com/hashicorp/consul | ≥ 1.8.0&&< 1.8.10 | 1.8.10go get github.com/hashicorp/consul@v1.8.10 |
| 🐹Go | github.com/hashicorp/consul | all versions | 1.7.14go get github.com/hashicorp/consul@v1.7.14 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/hashicorp/consul, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/hashicorp/consul to 1.9.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-25864 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2020-25864 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2020-25864. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2020-25864
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2020-25864 -u https://target- Template
- HashiCorp Consul/Consul Enterprise <=1.9.4 - Cross-Site Scripting
- Severity
- medium
- Impact
- Successful exploitation of this vulnerability could allow an attacker to execute arbitrary JavaScript code in the context of the victim's browser, leading to potential data theft, session hijacking, or defacement of the affected Consul/Consul Enterprise application.
- Remediation
- Fixed in 1.9.5, 1.8.10 and 1.7.14.
Template by ProjectDiscovery nuclei-templates (c-sh0), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2020-25864 in your dependencies?
O3 Security finds CVE-2020-25864 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.