CVE-2026-22256 — salvo
HIGHCVE-2026-22256 is a high-severity (CVSS 8.8) Cross-site Scripting (XSS) vulnerability in salvo. A fix is available for salvo — see the affected versions and patch details below.
Salvo is vulnerable to reflected XSS in the list_html function
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-22256.
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-2026-22256 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 376,715 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
salvoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Salvo is a Rust web backend framework. Prior to version 0.88.1, the function list_html generate an file view of a folder which include a render of the current path, in which its inserted in the HTML without proper sanitation, this leads to reflected XSS using the fact that request path is decoded and normalized in the matching stage but not is inserted raw in the html view (current.path), the only constraint here is for the root path (eg. /files in the PoC example) to have a sub directory (e.g common ones styles/scripts/etc…) so that the matching return the list HTML page instead of the Not Found page. This issue has been patched in version 0.88.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | salvo | all versions | 0.88.1cargo update -p salvo --precise 0.88.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for salvo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update salvo to 0.88.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-22256 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-2026-22256 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-22256. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-22256 in your dependencies?
O3 Security finds CVE-2026-22256 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.