Server-Side Request Forgery (SSRF) Affecting phpseclib package, versions <1.0.30-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-PHPSECLIB-17428800
- published23 Jun 2026
- disclosed22 Jun 2026
Introduced: 22 Jun 2026
CVE-2026-55599 (opens in a new tab)How to fix?
Upgrade Debian:unstable phpseclib to version 1.0.30-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream phpseclib package and not the phpseclib package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
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.