diff --git a/Library/Homebrew/cask/audit.rb b/Library/Homebrew/cask/audit.rb
index 1d6fa742e4df8..2c935ae351bb5 100644
--- a/Library/Homebrew/cask/audit.rb
+++ b/Library/Homebrew/cask/audit.rb
@@ -754,7 +754,7 @@ def cask_plist_min_os
     def audit_github_prerelease_version
       odebug "Auditing GitHub prerelease"
       user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*}) if online?
-      return if user.nil?
+      return if user.nil? || repo.nil?
 
       tag = SharedAudits.github_tag_from_url(cask.url)
       tag ||= cask.version
@@ -765,7 +765,7 @@ def audit_github_prerelease_version
     sig { void }
     def audit_gitlab_prerelease_version
       user, repo = get_repo_data(%r{https?://gitlab\.com/([^/]+)/([^/]+)/?.*}) if online?
-      return if user.nil?
+      return if user.nil? || repo.nil?
 
       odebug "Auditing GitLab prerelease"
 
@@ -781,7 +781,7 @@ def audit_github_repository_archived
       return if cask.deprecated? || cask.disabled?
 
       user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*}) if online?
-      return if user.nil?
+      return if user.nil? || repo.nil?
 
       metadata = SharedAudits.github_repo_data(user, repo)
       return if metadata.nil?
@@ -795,7 +795,7 @@ def audit_gitlab_repository_archived
       return if cask.deprecated? || cask.disabled?
 
       user, repo = get_repo_data(%r{https?://gitlab\.com/([^/]+)/([^/]+)/?.*}) if online?
-      return if user.nil?
+      return if user.nil? || repo.nil?
 
       odebug "Auditing GitLab repo archived"
 
@@ -810,7 +810,7 @@ def audit_github_repository
       return unless new_cask?
 
       user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*})
-      return if user.nil?
+      return if user.nil? || repo.nil?
 
       odebug "Auditing GitHub repo"
 
@@ -823,7 +823,7 @@ def audit_gitlab_repository
       return unless new_cask?
 
       user, repo = get_repo_data(%r{https?://gitlab\.com/([^/]+)/([^/]+)/?.*})
-      return if user.nil?
+      return if user.nil? || repo.nil?
 
       odebug "Auditing GitLab repo"
 
@@ -836,7 +836,7 @@ def audit_bitbucket_repository
       return unless new_cask?
 
       user, repo = get_repo_data(%r{https?://bitbucket\.org/([^/]+)/([^/]+)/?.*})
-      return if user.nil?
+      return if user.nil? || repo.nil?
 
       odebug "Auditing Bitbucket repo"
 
diff --git a/Library/Homebrew/formula_auditor.rb b/Library/Homebrew/formula_auditor.rb
index f0c63a2e51426..371635f967e16 100644
--- a/Library/Homebrew/formula_auditor.rb
+++ b/Library/Homebrew/formula_auditor.rb
@@ -582,15 +582,13 @@ def audit_eol
       metadata = SharedAudits.eol_data(name, formula.version.major)
       metadata ||= SharedAudits.eol_data(name, formula.version.major_minor)
 
-      return if metadata.blank? || metadata["eol"] == false
+      return if metadata.blank? || (eol_date = metadata["eol"]).blank?
 
-      see_url = "see #{Formatter.url("https://endoflife.date/#{name}")}"
-      if metadata["eol"] == true
-        problem "Product is EOL, #{see_url}"
-        return
-      end
+      message = "Product is EOL"
+      message += " since #{eol_date}" if Date.parse(eol_date.to_s) <= Date.today
+      message += ", see #{Formatter.url("https://endoflife.date/#{name}")}"
 
-      problem "Product is EOL since #{metadata["eol"]}, #{see_url}" if Date.parse(metadata["eol"]) <= Date.today
+      problem message
     end
 
     def audit_wayback_url
@@ -786,6 +784,8 @@ def audit_specs
         tag ||= stable.version
 
         if @online
+          return if owner.nil? || repo.nil?
+
           error = SharedAudits.gitlab_release(owner, repo, tag, formula:)
           problem error if error
         end
@@ -796,6 +796,8 @@ def audit_specs
         tag ||= formula.stable.specs[:tag]
 
         if @online
+          return if owner.nil? || repo.nil?
+
           error = SharedAudits.github_release(owner, repo, tag, formula:)
           problem error if error
         end
diff --git a/Library/Homebrew/utils/shared_audits.rb b/Library/Homebrew/utils/shared_audits.rb
index 3329ea1797fb4..b7cd07a4c496d 100644
--- a/Library/Homebrew/utils/shared_audits.rb
+++ b/Library/Homebrew/utils/shared_audits.rb
@@ -1,4 +1,4 @@
-# typed: true
+# typed: strict
 # frozen_string_literal: true
 
 require "utils/curl"
@@ -10,8 +10,9 @@ module SharedAudits
 
   module_function
 
+  sig { params(product: String, cycle: String).returns(T.nilable(T::Hash[String, T::Hash[Symbol, T.untyped]])) }
   def eol_data(product, cycle)
-    @eol_data ||= {}
+    @eol_data ||= T.let({}, T.nilable(T::Hash[String, T::Hash[String, T.untyped]]))
     @eol_data["#{product}/#{cycle}"] ||= begin
       out, _, status = Utils::Curl.curl_output("--location", "https://endoflife.date/api/#{product}/#{cycle}.json")
       json = JSON.parse(out) if status.success?
@@ -20,8 +21,9 @@ def eol_data(product, cycle)
     end
   end
 
+  sig { params(user: String, repo: String).returns(T.nilable(T::Hash[String, T.untyped])) }
   def github_repo_data(user, repo)
-    @github_repo_data ||= {}
+    @github_repo_data ||= T.let({}, T.nilable(T::Hash[String, T.untyped]))
     @github_repo_data["#{user}/#{repo}"] ||= GitHub.repository(user, repo)
 
     @github_repo_data["#{user}/#{repo}"]
@@ -31,10 +33,11 @@ def github_repo_data(user, repo)
     raise unless e.message.match?(GitHub::API::GITHUB_IP_ALLOWLIST_ERROR)
   end
 
+  sig { params(user: String, repo: String, tag: String).returns(T.nilable(T::Hash[String, T.untyped])) }
   def github_release_data(user, repo, tag)
     id = "#{user}/#{repo}/#{tag}"
     url = "#{GitHub::API_URL}/repos/#{user}/#{repo}/releases/tags/#{tag}"
-    @github_release_data ||= {}
+    @github_release_data ||= T.let({}, T.nilable(T::Hash[String, T.untyped]))
     @github_release_data[id] ||= GitHub::API.open_rest(url)
 
     @github_release_data[id]
@@ -44,6 +47,13 @@ def github_release_data(user, repo, tag)
     raise unless e.message.match?(GitHub::API::GITHUB_IP_ALLOWLIST_ERROR)
   end
 
+  sig {
+    params(
+      user: String, repo: String, tag: String, formula: T.nilable(Formula), cask: T.nilable(Cask::Cask),
+    ).returns(
+      T.nilable(String),
+    )
+  }
   def github_release(user, repo, tag, formula: nil, cask: nil)
     release = github_release_data(user, repo, tag)
     return unless release
@@ -63,8 +73,9 @@ def github_release(user, repo, tag, formula: nil, cask: nil)
     "#{tag} is a GitHub draft." if release["draft"]
   end
 
+  sig { params(user: String, repo: String).returns(T.nilable(T::Hash[String, T.untyped])) }
   def gitlab_repo_data(user, repo)
-    @gitlab_repo_data ||= {}
+    @gitlab_repo_data ||= T.let({}, T.nilable(T::Hash[String, T.untyped]))
     @gitlab_repo_data["#{user}/#{repo}"] ||= begin
       out, _, status = Utils::Curl.curl_output("https://gitlab.com/api/v4/projects/#{user}%2F#{repo}")
       json = JSON.parse(out) if status.success?
@@ -73,9 +84,10 @@ def gitlab_repo_data(user, repo)
     end
   end
 
+  sig { params(user: String, repo: String, tag: String).returns(T.nilable(T::Hash[String, T.untyped])) }
   def gitlab_release_data(user, repo, tag)
     id = "#{user}/#{repo}/#{tag}"
-    @gitlab_release_data ||= {}
+    @gitlab_release_data ||= T.let({}, T.nilable(T::Hash[String, T.untyped]))
     @gitlab_release_data[id] ||= begin
       out, _, status = Utils::Curl.curl_output(
         "https://gitlab.com/api/v4/projects/#{user}%2F#{repo}/releases/#{tag}", "--fail"
@@ -84,6 +96,13 @@ def gitlab_release_data(user, repo, tag)
     end
   end
 
+  sig {
+    params(
+      user: String, repo: String, tag: String, formula: T.nilable(Formula), cask: T.nilable(Cask::Cask),
+    ).returns(
+      T.nilable(String),
+    )
+  }
   def gitlab_release(user, repo, tag, formula: nil, cask: nil)
     release = gitlab_release_data(user, repo, tag)
     return unless release
@@ -100,6 +119,7 @@ def gitlab_release(user, repo, tag, formula: nil, cask: nil)
     "#{tag} is a GitLab pre-release."
   end
 
+  sig { params(user: String, repo: String).returns(T.nilable(String)) }
   def github(user, repo)
     metadata = github_repo_data(user, repo)
 
@@ -117,6 +137,7 @@ def github(user, repo)
     "GitHub repository too new (<30 days old)"
   end
 
+  sig { params(user: String, repo: String).returns(T.nilable(String)) }
   def gitlab(user, repo)
     metadata = gitlab_repo_data(user, repo)
 
@@ -132,6 +153,7 @@ def gitlab(user, repo)
     "GitLab repository too new (<30 days old)"
   end
 
+  sig { params(user: String, repo: String).returns(T.nilable(String)) }
   def bitbucket(user, repo)
     api_url = "https://api.bitbucket.org/2.0/repositories/#{user}/#{repo}"
     out, _, status = Utils::Curl.curl_output("--request", "GET", api_url)
@@ -163,6 +185,7 @@ def bitbucket(user, repo)
     "Bitbucket repository not notable enough (<30 forks and <75 watchers)"
   end
 
+  sig { params(url: String).returns(T.nilable(String)) }
   def github_tag_from_url(url)
     url = url.to_s
     tag = url.match(%r{^https://github\.com/[\w-]+/[\w-]+/archive/refs/tags/([^/]+)\.(tar\.gz|zip)$})
@@ -174,6 +197,7 @@ def github_tag_from_url(url)
     tag
   end
 
+  sig { params(url: String).returns(T.nilable(String)) }
   def gitlab_tag_from_url(url)
     url = url.to_s
     url.match(%r{^https://gitlab\.com/[\w-]+/[\w-]+/-/archive/([^/]+)/})