CVE-2025-46728Public exploitNetwork attack vector

Server denial of service via unbounded body accumulation

Published May 6, 2025 · Updated May 6, 2025

Resource exhaustion in cpp-httplib before 0.20.1 allows remote attackers to crash or hang servers via oversized request bodies. The read_content_chunked function and associated stream logic accumulate chunk data in req.body or a content receiver without enforcing the configured total payload limit. No authentication or valid route is required because body parsing occurs before routing, and continued unterminated chunks exhaust process or shared-host memory.

CVSS severity7.5
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Resource exhaustion in cpp-httplib before 0.20.1 allows remote attackers to crash or hang servers via oversized request bodies. The read_content_chunked function and associated stream logic accumulate chunk data in req.body or a content receiver without enforcing the configured total payload limit. No authentication or valid route is required because body parsing occurs before routing, and continued unterminated chunks exhaust process or shared-host memory.

The record

CVE
CVE-2025-46728
Published
May 6, 2025
Updated
May 6, 2025
Vendor
Yuji Hirose
Product
cpp-httplib
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2025CVE publishedPublication date reported by the CVE source.
  2. May 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.20.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Yuji Hirose · cpp-httplibversion=< 0.20.1

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo