CVE-2025-4947Public exploitNetwork attack vector

QUIC peer impersonation via skipped IP certificate check

Published May 28, 2025 · Updated May 28, 2025

Improper certificate validation in curl 8.8.0 through 8.13.0 allows man-in-the-middle attackers to impersonate QUIC peers. In Curl_vquic_tls_verify_peer, the wolfSSL branch checks the certificate only when peer->sni is set, leaving IP-address URLs unchecked. The flaw requires wolfSSL as the QUIC TLS backend and an IP-address URL; successful interception exposes or alters transferred data.

CVSS severity6.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in curl 8.8.0 through 8.13.0 allows man-in-the-middle attackers to impersonate QUIC peers. In Curl_vquic_tls_verify_peer, the wolfSSL branch checks the certificate only when peer->sni is set, leaving IP-address URLs unchecked. The flaw requires wolfSSL as the QUIC TLS backend and an IP-address URL; successful interception exposes or alters transferred data.

The record

CVE
CVE-2025-4947
Published
May 28, 2025
Updated
May 28, 2025
Vendor
curl
Product
curl
Classifications
CWE-295, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 28, 2025CVE publishedPublication date reported by the CVE source.
  2. May 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=8.10.0 <=8.10.0
  2. Affected versionversion=8.10.1 <=8.10.1
  3. Affected versionversion=8.11.0 <=8.11.0
  4. Affected versionversion=8.11.1 <=8.11.1
  5. Affected versionversion=8.12.0 <=8.12.0
  6. Affected versionversion=8.12.1 <=8.12.1
  7. Affected versionversion=8.13.0 <=8.13.0
  8. Affected versionversion=8.8.0 <=8.8.0
  9. Affected versionversion=8.9.0 <=8.9.0
  10. Affected versionversion=8.9.1 <=8.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

curl · curlversion=8.10.0 <=8.10.0; version=8.10.1 <=8.10.1; version=8.11.0 <=8.11.0; version=8.11.1 <=8.11.1; version=8.12.0 <=8.12.0; version=8.12.1 <=8.12.1; version=8.13.0 <=8.13.0; version=8.8.0 <=8.8.0; version=8.9.0 <=8.9.0; version=8.9.1 <=8.9.1

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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-295Improper Certificate Validation
T1557Adversary-in-the-Middle

Public exploit references

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

Technologies

Your stack

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Your stack

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