Salvo Affected by Denial of Service via Unbounded Memory Allocation in Form Data Parsing

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-33241: 0.44% estimated exploitation activity in the next 30 days; percentile 38.69 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Salvo's form data parsing implementations (formdata() method and Extractible macro) do not enforce payload size limits before reading request bodies into memory. This allows attackers to cause Out-of-Memory (OOM) conditions by sending extremely large payloads, leading to service crashes and denial of service. Details Vulnerability Description Three attack vectors exist in Salvo's form handling: 1. URL-encoded form data (application/x-www-form-urlencoded) - Request::formdata() calls BodyExt::collect(body) which reads the entire body into memory without size checking - Affects handlers using req.formdata().await directly 2. Multipart form data (multipart/form-data) - Similar unbounded memory allocation during parsing - Affects handlers processing multipart uploads 3. Extractible macro - #[derive(Extractible)] with #[salvo(extract(defaultsource(from = "body")))] internally calls formdata() - Vulnerabilities propagate to all extractors using body sources Root Cause The…

Published by the source

19 Mar 2026, 12:44 UTC

Last modified by the source

25 Mar 2026, 20:48 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-pp9r-xg4c-8j4x

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# Patch Next advisory brief: CVE-2026-33241

Advisory: Salvo Affected by Denial of Service via Unbounded Memory Allocation in Form Data Parsing
IDs: CVE-2026-33241, GHSA-pp9r-xg4c-8j4x
Record: https://patchnext.com/advisories/cve-2026-33241 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: salvo 0.89.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io salvo: affected < 0.89.3; fixed in 0.89.3

## Suggested inspection (read-only)
- crates.io salvo: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on salvo.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-pp9r-xg4c-8j4x (GitHub-reviewed advisory GHSA-pp9r-xg4c-8j4x lists affected ranges: crates.io salvo >=0 <0.89.3)

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