[OE-core][scarthgap][PATCH 1/6] libxml2: Security Fix for CVE-2026-86137

[Siddharth <sdoshi@mvista.com>]

From: Siddharth Doshi <sdoshi@mvista.com>

Picking patch as per [1], and same patch is mentioned in [2]

References:
[1] https://nvd.nist.gov/vuln/detail/CVE-2026-86137
[2] https://security-tracker.debian.org/tracker/CVE-2026-86137

Signed-off-by: Siddharth Doshi <sdoshi@mvista.com>
---
 .../libxml/libxml2/CVE-2026-86137.patch       | 48 +++++++++++++++++++
 meta/recipes-core/libxml/libxml2_2.12.10.bb   |  1 +
 2 files changed, 49 insertions(+)
 create mode 100644 meta/recipes-core/libxml/libxml2/CVE-2026-86137.patch

diff --git a/meta/recipes-core/libxml/libxml2/CVE-2026-86137.patch b/meta/recipes-core/libxml/libxml2/CVE-2026-86137.patch
new file mode 100644
index 0000000000..e8ccd93142
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/CVE-2026-86137.patch
@@ -0,0 +1,48 @@
+From 76fe08d97de88bfaef2f7d5cd27f11954cc5bee2 Mon Sep 17 00:00:00 2001
+From: Hieu Le Minh <leminhhieu.opensource@gmail.com>
+Date: Sat, 18 Apr 2026 21:18:24 +0700
+Subject: [PATCH] xmlregexp: Prevent out-of-bounds read in NXT macro
+
+Fixes: https://gitlab.gnome.org/GNOME/libxml2/-/issues/1099
+
+Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxml2/-/commit/76fe08d97de88bfaef2f7d5cd27f11954cc5bee2]
+CVE: CVE-2026-86137
+Signed-off-by: Siddharth Doshi <sdoshi@mvista.com>
+---
+ xmlregexp.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/xmlregexp.c b/xmlregexp.c
+index f434a0c..5e15311 100644
+--- a/xmlregexp.c
++++ b/xmlregexp.c
+@@ -56,7 +56,9 @@
+     xmlRegexpErrCompile(ctxt, str);
+ #define NEXT ctxt->cur++
+ #define CUR (*(ctxt->cur))
+-#define NXT(index) (ctxt->cur[index])
++#define NXT(index)									\
++    (((size_t)(ctxt->cur + index - ctxt->string) < ctxt->len)				\
++      ? ctxt->cur[index] : 0)
+ 
+ #define NEXTL(l) ctxt->cur += l;
+ #define XML_REG_STRING_SEPARATOR '|'
+@@ -245,6 +247,7 @@ typedef xmlRegParserCtxt *xmlRegParserCtxtPtr;
+ struct _xmlAutomata {
+     xmlChar *string;
+     xmlChar *cur;
++    size_t len;
+ 
+     int error;
+     int neg;
+@@ -700,6 +703,7 @@ xmlRegNewParserCtxt(const xmlChar *string) {
+     memset(ret, 0, sizeof(xmlRegParserCtxt));
+     if (string != NULL)
+ 	ret->string = xmlStrdup(string);
++	ret->len = strlen((const char *) ret->string);
+     ret->cur = ret->string;
+     ret->neg = 0;
+     ret->negs = 0;
+-- 
+2.34.1
+
diff --git a/meta/recipes-core/libxml/libxml2_2.12.10.bb b/meta/recipes-core/libxml/libxml2_2.12.10.bb
index d476ba14b6..e4db345af4 100644
--- a/meta/recipes-core/libxml/libxml2_2.12.10.bb
+++ b/meta/recipes-core/libxml/libxml2_2.12.10.bb
@@ -32,6 +32,7 @@ SRC_URI += "http://www.w3.org/XML/Test/xmlts20130923.tar;subdir=${BP};name=testt
            file://CVE-2026-0992-03.patch \
            file://CVE-2026-1757.patch \
            file://CVE-2026-11979.patch \
+           file://CVE-2026-86137.patch \
            "
 
 SRC_URI[archive.sha256sum] = "c3d8c0c34aa39098f66576fe51969db12a5100b956233dc56506f7a8679be995"
-- 
2.34.1