diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -821,6 +821,8 @@ class basefilectx(object):
         return self._changectx.phasestr()
     def obsolete(self):
         return self._changectx.obsolete()
+    def instabilities(self):
+        return self._changectx.instabilities()
     def manifest(self):
         return self._changectx.manifest()
     def changectx(self):
diff --git a/mercurial/hgweb/webutil.py b/mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py
+++ b/mercurial/hgweb/webutil.py
@@ -362,6 +362,7 @@ def commonentry(repo, ctx):
         'extra': ctx.extra(),
         'phase': ctx.phasestr(),
         'obsolete': ctx.obsolete(),
+        'instabilities': [{"name": i} for i in ctx.instabilities()],
         'branch': nodebranchnodefault(ctx),
         'inbranch': nodeinbranch(repo, ctx),
         'branches': nodebranchdict(repo, ctx),