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VulnerabilityPublished Updated

CVE-2025-5025: curl · Improper Certificate Validation

Affects curlSource CVE Database V5

0

Not known to be exploited · CVSS 4.8 Medium.

Data as of 26 Oct 2026, 09:08 UTC

CVSS 3.1 base score
4.8Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 May 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
curl curlAffected
  • =8.13.0
  • =8.12.1
  • =8.12.0
  • =8.11.1
  • =8.11.0
  • =8.10.1
  • =8.10.0
  • =8.9.1
  • =8.9.0
  • =8.8.0
  • =8.7.1
  • =8.7.0
  • =8.6.0
  • =8.5.0
Fixed in–

AI-suggested

To mitigate this vulnerability, European organizations should: 1) Avoid using curl with wolfSSL as the TLS backend for QUIC and HTTP/3 connections until a patch is released. 2) Temporarily disable HTTP/3 or QUIC support in curl-based applications if certificate pinning is critical. 3) Monitor curl updates and apply patches promptly once available. 4) Implement additional network-level protections such as TLS interception detection and anomaly monitoring to identify suspicious MITM attempts. 5) Where possible, switch to a different TLS backend supported by curl that correctly enforces certificate pinning with QUIC and HTTP/3 (e.g., OpenSSL or others) after verifying compatibility. 6) Conduct thorough security testing of applications using curl with HTTP/3 and QUIC to ensure no inadvertent exposure. 7) Educate developers and system administrators about this limitation to avoid false assumptions about pinning effectiveness in affected configurations. These steps go beyond generic advice by focusing on configuration changes, backend selection, and proactive monitoring tailored to this specific flaw.

Description

libcurl supports *pinning* of the server certificate public key for HTTPS transfers. Due to an omission, this check is not performed when connecting with QUIC for HTTP/3, when the TLS backend is wolfSSL. Documentation says the option works with wolfSSL, failing to specify that it does not for QUIC and HTTP/3. Since pinning makes the transfer succeed if the pin is fine, users could unwittingly connect to an impostor server without noticing.

References

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