CVE-2025-5025: curl · Improper Certificate Validation
Affects curlSource CVE Database V5
Not known to be exploited · CVSS 4.8 Medium.
Data as of 26 Oct 2026, 09:08 UTC
- 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:NExploitation evidence
Disclosed: evidence found.
CVE published 28 May 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| curl curl | Affected
| 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.