CVE-2026-74888

This CVE exposes a fundamental ergonomic failure in how PHP's openssl_encrypt handles password-based key derivation — the vulnerability isn't simply that someone chose a weak iteration count, but that the API permits composing PBKDF2 with iterations=1 inside an outer loop without any validation, warning, or friction. This is a design failure: developers who needed password-based encryption were forced to manually compose PBKDF2, and the library provided no guardrails against catastrophic misconfiguration. The pattern of PBKDF2 with iterations=1 wrapped in a loop suggests a developer who understood that key derivation was necessary but lacked the signal or defaults to implement it correctly. The outer-loop structure implies someone parameterized iteration count to make it 'configurable' — a reasonable-seeming design decision that created a footgun. This is precisely the failure mode the security community has seen before: OpenSSL EVP_EncryptInit (2014), PHP mcrypt misconfigurations (2015), Java JCE misuse (2019) — all share the same ergonomic signature of libraries exposing PBKDF2 parameters without validation or sane defaults. For defenders: verify your implementation does not manually compose PBKDF2 with low iteration counts in any loop structure. Check for any configurable iteration-count parameters passed from application logic into key derivation. If you use openssl_encrypt with password-based encryption, ensure you're not manually constructing the PBKDF2 call — use higher-level abstractions or validate that iterations exceed 100,000. The fix in 1.4.0 should be reviewed to determine whether it addresses the API surface that permitted this miscomposition or merely patches the specific iteration count — if the parameterization path remains, the same failure mode can recur in future code changes.

Reviewed through automated stages and approved by a human before publication.