What’s Vulnerable › Vulnerabilities

CVE-2026-82208: wolfSSL CA-cache hit overrides callback

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-09-06 · updated 2026-09-15
• Weakness: CWE-295

Description

With the wolfSSL backend, when CA caching is enabled and an `CURLOPT_SSL_CTX_FUNCTION` callback replaces the trust store, libcurl can silently reinstall the cached store after the callback returns. A certificate trusted by the cached store but rejected by the callback-selected store is then incorrectly accepted.

Affected products

• curl: from 8.9.1 before 8.22.0 — fixed in 8.22.0

How to fix

Upgrade to a fixed version: curl 8.22.0. Check the vendor advisory for mitigations.

References

• https://curl.se/docs/CVE-2026-82208.html
• https://curl.se/docs/CVE-2026-82208.json
• https://hackerone.com/reports/3973090

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