Integer Overflow/Infinite Loop in the http crate

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2020-25574: 2.53% estimated exploitation activity in the next 30 days; percentile 84.92 (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.

HeaderMap::reserve() used usize::nextpoweroftwo() to calculate the increased capacity. However, nextpoweroftwo() silently overflows to 0 if given a sufficiently large number in release mode. If the map was not empty when the overflow happens, the library will invoke self.grow(0) and start infinite probing. This allows an attacker who controls the argument to reserve() to cause a potential denial of service (DoS). The flaw was corrected in 0.1.20 release of http crate.

Published by the source

25 Aug 2021, 21:01 UTC

Last modified by the source

13 Jun 2023, 18:21 UTC

Source last checked

26 Oct 2026, 15:34 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x7vr-c387-8w57

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# Patch Next advisory brief: CVE-2020-25574

Advisory: Integer Overflow/Infinite Loop in the http crate
IDs: CVE-2020-25574, GHSA-x7vr-c387-8w57
Record: https://patchnext.com/advisories/cve-2020-25574 (revision 1, source checked 26 Oct 2026, 15:34 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: http 0.1.20. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io http: affected < 0.1.20; fixed in 0.1.20

## Suggested inspection (read-only)
- crates.io http: 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 http.
- 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-x7vr-c387-8w57 (GitHub-reviewed advisory GHSA-x7vr-c387-8w57 lists affected ranges: crates.io http >=0 <0.1.20)

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