Security context

What an agent needs to avoid regressing past fixes and find the next vuln in this repo.

ruby/psych

              master @ 4ebee95
            

Fixes

CVEs

HIGH

Peak severity

Highlights

Auth Bypass: 1 prior fix. Scrutinize any change in this area.

lib/psych/visitors/to_ruby.rb: most-fixed (2 issues). Treat as high-risk during review.

1 high-severity fix in this history; regressions here are high-impact.

Recurring patterns

The bug types that recur here, drawn from past fixes, not open vulnerabilities.

Auth Bypass: Attackers can bypass 'init_with' validation of target classes by utilizing tags like !ruby/hash-with-ivars or !map, which resolve to non-Hash subclasses if structural verification is missing.

Insecure Deserialization: Bypasses in safe_load occur when specific YAML tags (such as '!ruby/encoding') resolve directly to core Ruby classes (like Encoding) without being subjected to the permitted_classes check.