Cyber Resilience

CVE-2025-4947

Crypto Weakness in Haxx Curl 8.8.0 – 8.14.0

Public PoCCrypto Weakness
Published
28 May 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0025 16th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-4947 is a medium-severity Improper Certificate Validation (CWE-295) vulnerability in Haxx Curl. Its CVSS base score is 6.5 (Medium).

Operationally, ranked at the 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SC-17 (Public Key Infrastructure Certificates) and SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

libcurl accidentally skips the certificate verification for QUIC connections when connecting to a host specified as an IP address in the URL. Therefore, it does not detect impostors or man-in-the-middle attacks.

CWE(s)
CWE-295

Related Threats

CVEs Like This One

CVE-2025-13034Same product: Haxx Curl
CVE-2024-0853Same product: Haxx Curl
CVE-2026-11564Same product: Haxx Curl
CVE-2026-12064Same product: Haxx Curl
CVE-2026-8286Same product: Haxx Curl
CVE-2025-14819Same product: Haxx Curl
CVE-2026-7009Same product: Haxx Curl
CVE-2025-5025Same product: Haxx Curl
CVE-2026-4873Same product: Haxx Curl
CVE-2025-5399Same product: Haxx Curl

Affected Assets

haxx
curl
8.8.0 — 8.14.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-8 Transmission Confidentiality and Integrity
  • SC-17 Public Key Infrastructure Certificates
  • SC-23 Session Authenticity
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 12 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SC-8 Transmission Confidentiality and Integrity good match
prevent

Requires cryptographic mechanisms that protect QUIC session integrity and confidentiality, directly enforcing certificate validation to block the IP-address MITM flaw.

SC-17 Public Key Infrastructure Certificates good match
prevent

Mandates proper issuance, management and validation of PKI certificates, addressing the exact certificate-verification skip for QUIC+IP URLs.

SC-23 Session Authenticity partial match
prevent

Ensures session authenticity protections that would detect or block impostor QUIC endpoints when certificate checks are bypassed.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 mostly match
prevents

Certificate-based authentication of users/services/hardware directly depends on correct validation.

PR.DS-02 mostly match
prevents

Proper certificate validation is a core mechanism for protecting data-in-transit confidentiality and integrity.

PR.PS-06 mostly match
prevents

Secure development practices explicitly include implementing correct certificate validation logic.

ID.RA-09 partial match
prevents

Assessing authenticity/integrity of acquired software often relies on code-signing certificate validation.

PR.AA-04 partial match
prevents

Identity assertions conveyed via certificates require validation to be verified.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.24 Use of cryptography partial match
prevents

Requiring issuance and validation of public-key certificates under an approved policy reduces the chance that certificates with improper validation will be trusted.

Hardening callouts derived

Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).

Oracle Linux 8 (2 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. via CWE-295
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-295
RHEL 7 (1 rule)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-295
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-295
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-295

References