phpseclib is a PHP secure communications library. From 0.1.1 until 1.0.30, 2.0.55, and 3.0.54, when an application validates an untrusted X.509 certificate with phpseclib, X509::validateSignature() reads a URL out of that certificate's Authority Information Access (AIA) extension and connects to it. Attacker who supplies certificate fully controls host, port, and path of that connection. URL fetching is enabled by default, and no destination is blocked. An unauthenticated attacker can therefore make a validating server open connections to internal hosts and ports it should never reach, for example loopback 127.0.0.1, cloud metadata address 169.254.169.254, and internal-only services. This is a server-side request forgery (SSRF) caused by an insecure default. This vulnerability is fixed in 1.0.30, 2.0.55, and 3.0.54.
References
| Link | Resource |
|---|---|
| https://github.com/phpseclib/phpseclib/security/advisories/GHSA-m557-wrgg-6rp4 | Exploit Mitigation Vendor Advisory |
| https://github.com/phpseclib/phpseclib/security/advisories/GHSA-m557-wrgg-6rp4 | Exploit Mitigation Vendor Advisory |
Configurations
Configuration 1 (hide)
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History
26 Jun 2026, 20:10
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Phpseclib phpseclib
Phpseclib |
|
| CPE | cpe:2.3:a:phpseclib:phpseclib:*:*:*:*:*:*:*:* | |
| References | () https://github.com/phpseclib/phpseclib/security/advisories/GHSA-m557-wrgg-6rp4 - Exploit, Mitigation, Vendor Advisory |
23 Jun 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/phpseclib/phpseclib/security/advisories/GHSA-m557-wrgg-6rp4 - |
22 Jun 2026, 21:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-06-22 21:16
Updated : 2026-06-26 20:10
NVD link : CVE-2026-55599
Mitre link : CVE-2026-55599
CVE.ORG link : CVE-2026-55599
JSON object : View
Products Affected
phpseclib
- phpseclib
CWE
CWE-918
Server-Side Request Forgery (SSRF)