diff --git a/actions/ql/lib/change-notes/2025-03-20.md b/actions/ql/lib/change-notes/2025-03-20.md
new file mode 100644
index 000000000000..1f8b74308376
--- /dev/null
+++ b/actions/ql/lib/change-notes/2025-03-20.md
@@ -0,0 +1,5 @@
+---
+category: fix
+---
+* The query `actions/code-injection/medium` now produces alerts for injection
+  vulnerabilities on `pull_request` events.
\ No newline at end of file
diff --git a/actions/ql/lib/ext/config/context_event_map.yml b/actions/ql/lib/ext/config/context_event_map.yml
index 930a4344e12e..541ac8b9a8f6 100644
--- a/actions/ql/lib/ext/config/context_event_map.yml
+++ b/actions/ql/lib/ext/config/context_event_map.yml
@@ -30,6 +30,9 @@ extensions:
       - ["pull_request_review_comment", "github.event.review"] 
       - ["pull_request_review_comment", "github.head_ref"] 
       - ["pull_request_review_comment", "github.event.changes"] 
+      - ["pull_request", "github.event.pull_request"] 
+      - ["pull_request", "github.head_ref"] 
+      - ["pull_request", "github.event.changes"] 
       - ["pull_request_target", "github.event.pull_request"] 
       - ["pull_request_target", "github.head_ref"] 
       - ["pull_request_target", "github.event.changes"] 
diff --git a/actions/ql/lib/ext/config/externally_triggereable_events.yml b/actions/ql/lib/ext/config/externally_triggereable_events.yml
index e1bfca52ea79..ae47c684095d 100644
--- a/actions/ql/lib/ext/config/externally_triggereable_events.yml
+++ b/actions/ql/lib/ext/config/externally_triggereable_events.yml
@@ -12,6 +12,7 @@ extensions:
       - ["pull_request_comment"]
       - ["pull_request_review"]
       - ["pull_request_review_comment"]
+      - ["pull_request"]
       - ["pull_request_target"]
       - ["workflow_run"] # depending on branch filter
       - ["workflow_call"] # depending on caller
diff --git a/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionCritical.expected b/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionCritical.expected
index d44205e4fb92..af788f6280b2 100644
--- a/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionCritical.expected
+++ b/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionCritical.expected
@@ -400,6 +400,7 @@ nodes
 | .github/workflows/level0.yml:44:20:44:49 | github.event.issue.body | semmle.label | github.event.issue.body |
 | .github/workflows/level0.yml:69:35:69:66 | github.event.comment.body | semmle.label | github.event.comment.body |
 | .github/workflows/level1.yml:37:38:37:81 | github.event.workflow_run.head_branch | semmle.label | github.event.workflow_run.head_branch |
+| .github/workflows/priv_pull_request.yml:14:21:14:57 | github.event.pull_request.body | semmle.label | github.event.pull_request.body |
 | .github/workflows/pull_request_review.yml:7:19:7:56 | github.event.pull_request.title | semmle.label | github.event.pull_request.title |
 | .github/workflows/pull_request_review.yml:8:19:8:55 | github.event.pull_request.body | semmle.label | github.event.pull_request.body |
 | .github/workflows/pull_request_review.yml:9:19:9:61 | github.event.pull_request.head.label | semmle.label | github.event.pull_request.head.label |
@@ -629,6 +630,7 @@ nodes
 | .github/workflows/test19.yml:124:9:129:6 | Run Step: title3 [title] | semmle.label | Run Step: title3 [title] |
 | .github/workflows/test19.yml:125:14:128:50 | TITLE=$(gh issue view "$ISSUE_NUMBER" --json title,author)\nTITLE=$(echo $TITLE \| jq -r '.title')\necho "title=$TITLE" >> "$GITHUB_OUTPUT"\n | semmle.label | TITLE=$(gh issue view "$ISSUE_NUMBER" --json title,author)\nTITLE=$(echo $TITLE \| jq -r '.title')\necho "title=$TITLE" >> "$GITHUB_OUTPUT"\n |
 | .github/workflows/test19.yml:129:21:129:52 | steps.title3.outputs.title | semmle.label | steps.title3.outputs.title |
+| .github/workflows/test20.yml:15:54:15:94 | github.event.pull_request.head.ref | semmle.label | github.event.pull_request.head.ref |
 | .github/workflows/test21.yml:22:35:22:73 | github.event.head_commit.message | semmle.label | github.event.head_commit.message |
 | .github/workflows/test21.yml:23:36:23:74 | github.event.head_commit.message | semmle.label | github.event.head_commit.message |
 | .github/workflows/test21.yml:24:50:24:88 | github.event.head_commit.message | semmle.label | github.event.head_commit.message |
diff --git a/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionMedium.expected b/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionMedium.expected
index 36b6019c10e9..6c948d9559ea 100644
--- a/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionMedium.expected
+++ b/actions/ql/test/query-tests/Security/CWE-094/CodeInjectionMedium.expected
@@ -400,6 +400,7 @@ nodes
 | .github/workflows/level0.yml:44:20:44:49 | github.event.issue.body | semmle.label | github.event.issue.body |
 | .github/workflows/level0.yml:69:35:69:66 | github.event.comment.body | semmle.label | github.event.comment.body |
 | .github/workflows/level1.yml:37:38:37:81 | github.event.workflow_run.head_branch | semmle.label | github.event.workflow_run.head_branch |
+| .github/workflows/priv_pull_request.yml:14:21:14:57 | github.event.pull_request.body | semmle.label | github.event.pull_request.body |
 | .github/workflows/pull_request_review.yml:7:19:7:56 | github.event.pull_request.title | semmle.label | github.event.pull_request.title |
 | .github/workflows/pull_request_review.yml:8:19:8:55 | github.event.pull_request.body | semmle.label | github.event.pull_request.body |
 | .github/workflows/pull_request_review.yml:9:19:9:61 | github.event.pull_request.head.label | semmle.label | github.event.pull_request.head.label |
@@ -629,6 +630,7 @@ nodes
 | .github/workflows/test19.yml:124:9:129:6 | Run Step: title3 [title] | semmle.label | Run Step: title3 [title] |
 | .github/workflows/test19.yml:125:14:128:50 | TITLE=$(gh issue view "$ISSUE_NUMBER" --json title,author)\nTITLE=$(echo $TITLE \| jq -r '.title')\necho "title=$TITLE" >> "$GITHUB_OUTPUT"\n | semmle.label | TITLE=$(gh issue view "$ISSUE_NUMBER" --json title,author)\nTITLE=$(echo $TITLE \| jq -r '.title')\necho "title=$TITLE" >> "$GITHUB_OUTPUT"\n |
 | .github/workflows/test19.yml:129:21:129:52 | steps.title3.outputs.title | semmle.label | steps.title3.outputs.title |
+| .github/workflows/test20.yml:15:54:15:94 | github.event.pull_request.head.ref | semmle.label | github.event.pull_request.head.ref |
 | .github/workflows/test21.yml:22:35:22:73 | github.event.head_commit.message | semmle.label | github.event.head_commit.message |
 | .github/workflows/test21.yml:23:36:23:74 | github.event.head_commit.message | semmle.label | github.event.head_commit.message |
 | .github/workflows/test21.yml:24:50:24:88 | github.event.head_commit.message | semmle.label | github.event.head_commit.message |
@@ -706,6 +708,7 @@ subpaths
 | .github/workflows/inter-job2.yml:45:20:45:53 | needs.job1.outputs.job_output | .github/workflows/inter-job2.yml:22:9:26:6 | Uses Step: source | .github/workflows/inter-job2.yml:45:20:45:53 | needs.job1.outputs.job_output | Potential code injection in $@, which may be controlled by an external user. | .github/workflows/inter-job2.yml:45:20:45:53 | needs.job1.outputs.job_output | ${{needs.job1.outputs.job_output}} |
 | .github/workflows/inter-job4.yml:44:20:44:53 | needs.job1.outputs.job_output | .github/workflows/inter-job4.yml:22:9:26:6 | Uses Step: source | .github/workflows/inter-job4.yml:44:20:44:53 | needs.job1.outputs.job_output | Potential code injection in $@, which may be controlled by an external user. | .github/workflows/inter-job4.yml:44:20:44:53 | needs.job1.outputs.job_output | ${{needs.job1.outputs.job_output}} |
 | .github/workflows/inter-job5.yml:45:20:45:53 | needs.job1.outputs.job_output | .github/workflows/inter-job5.yml:45:20:45:53 | needs.job1.outputs.job_output | .github/workflows/inter-job5.yml:45:20:45:53 | needs.job1.outputs.job_output | Potential code injection in $@, which may be controlled by an external user. | .github/workflows/inter-job5.yml:45:20:45:53 | needs.job1.outputs.job_output | ${{needs.job1.outputs.job_output}} |
+| .github/workflows/priv_pull_request.yml:14:21:14:57 | github.event.pull_request.body | .github/workflows/priv_pull_request.yml:14:21:14:57 | github.event.pull_request.body | .github/workflows/priv_pull_request.yml:14:21:14:57 | github.event.pull_request.body | Potential code injection in $@, which may be controlled by an external user. | .github/workflows/priv_pull_request.yml:14:21:14:57 | github.event.pull_request.body | ${{ github.event.pull_request.body }} |
 | .github/workflows/push.yml:7:19:7:57 | github.event.commits[11].message | .github/workflows/push.yml:7:19:7:57 | github.event.commits[11].message | .github/workflows/push.yml:7:19:7:57 | github.event.commits[11].message | Potential code injection in $@, which may be controlled by an external user. | .github/workflows/push.yml:7:19:7:57 | github.event.commits[11].message | ${{ github.event.commits[11].message }} |
 | .github/workflows/push.yml:8:19:8:62 | github.event.commits[11].author.email | .github/workflows/push.yml:8:19:8:62 | github.event.commits[11].author.email | .github/workflows/push.yml:8:19:8:62 | github.event.commits[11].author.email | Potential code injection in $@, which may be controlled by an external user. | .github/workflows/push.yml:8:19:8:62 | github.event.commits[11].author.email | ${{ github.event.commits[11].author.email }} |
 | .github/workflows/push.yml:9:19:9:61 | github.event.commits[11].author.name | .github/workflows/push.yml:9:19:9:61 | github.event.commits[11].author.name | .github/workflows/push.yml:9:19:9:61 | github.event.commits[11].author.name | Potential code injection in $@, which may be controlled by an external user. | .github/workflows/push.yml:9:19:9:61 | github.event.commits[11].author.name | ${{ github.event.commits[11].author.name }} |