From 86c25c06c92c18fef862d1cc9459cf78a22f72c7 Mon Sep 17 00:00:00 2001
From: Viktor Szakats <commit@vsz.me>
Date: Thu, 19 Mar 2026 00:11:33 +0100
Subject: [PATCH] x509asn1: fix to return error in an error case from
 `encodeOID()`

Found by Codex Security

Follow-up to d8b0318ad6da7e51f7c94df00a5f165a52580889 #3582

Closes #20991
---
 lib/vtls/x509asn1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/vtls/x509asn1.c b/lib/vtls/x509asn1.c
index b687a60193..fd45285b49 100644
--- a/lib/vtls/x509asn1.c
+++ b/lib/vtls/x509asn1.c
@@ -442,7 +442,7 @@ static CURLcode encodeOID(struct dynbuf *store,
     x = 0;
     do {
       if(x & 0xFF000000)
-        return CURLE_OK;
+        return CURLE_BAD_FUNCTION_ARGUMENT;
       else if(beg == end)
         return CURLE_BAD_FUNCTION_ARGUMENT;
       y = *(const unsigned char *)beg++;