ae1b9adc9d85808683118f771703aeb8970306bf
braney
  Sat Aug 22 10:19:03 2026 -0700
hubApi: add X-Content-Type-Options: nosniff to responses, refs #38163

Set the nosniff header ahead of the Content-Type on every hubApi output
path (JSON, text, and html), so responses declare their type explicitly.

diff --git src/hg/hubApi/blat.c src/hg/hubApi/blat.c
index 4dfe07a55a9..251a39a460e 100644
--- src/hg/hubApi/blat.c
+++ src/hg/hubApi/blat.c
@@ -124,45 +124,47 @@
         toLowerN(seq->dna, seq->size);
         subChar(seq->dna, 'u', 't');
         }
     }
 if (seqList != NULL && seqList->name[0] == 0)
     {
     freeMem(seqList->name);
     seqList->name = cloneString("YourSeq");
     }
 }
 
 static void writePslOutput(struct psl *pslList, struct blatType *bt)
 /* PSL text output path (output=psl). */
 {
 hPrintDisable();
+puts("X-Content-Type-Options: nosniff");
 puts("Content-Type:text/plain\n");
 pslxWriteHead(stdout, bt->qType, bt->tType);
 struct psl *psl;
 int n = 0;
 for (psl = pslList; psl != NULL && n < maxItemsOutput; psl = psl->next, ++n)
     pslTabOut(psl, stdout);
 }
 
 static void writeLegacyJsonOutput(struct psl *pslList, char *db)
 /* Byte-for-byte the same JSON shape hgBlat?output=json emits: a top-level
  * object with "track":"blat", "genome", a "fields" header array, and "blat"
  * as an array of arrays (one row per PSL).
  * Triggered by format=hgblat or jsonOutputArrays=1. */
 {
 hPrintDisable();
+puts("X-Content-Type-Options: nosniff");
 puts("Content-Type:text/plain\n");
 pslWriteAllJson(pslList, stdout, db, TRUE);
 }
 
 static void writePslAsObject(struct jsonWrite *jw, struct psl *psl)
 /* Write one PSL hit as a JSON object with named keys. */
 {
 int b;
 jsonWriteObjectStart(jw, NULL);
 jsonWriteNumber(jw, "matches", psl->match);
 jsonWriteNumber(jw, "misMatches", psl->misMatch);
 jsonWriteNumber(jw, "repMatches", psl->repMatch);
 jsonWriteNumber(jw, "nCount", psl->nCount);
 jsonWriteNumber(jw, "qNumInsert", psl->qNumInsert);
 jsonWriteNumber(jw, "qBaseInsert", psl->qBaseInsert);