From 140424d8f3dcab7f51de01446783bd248eec159b Mon Sep 17 00:00:00 2001
From: "Piotr P. Karwasz" <piotr@github.copernik.eu>
Date: Fri, 10 Apr 2026 21:32:45 +0200
Subject: [PATCH] Improve GHSA-h383-gmxw-35v2

---
 .../GHSA-h383-gmxw-35v2.json                  | 52 +++++++++++++++++--
 1 file changed, 48 insertions(+), 4 deletions(-)

diff --git a/advisories/unreviewed/2026/04/GHSA-h383-gmxw-35v2/GHSA-h383-gmxw-35v2.json b/advisories/unreviewed/2026/04/GHSA-h383-gmxw-35v2/GHSA-h383-gmxw-35v2.json
index 7065b713cfbd4..9924b691aee60 100644
--- a/advisories/unreviewed/2026/04/GHSA-h383-gmxw-35v2/GHSA-h383-gmxw-35v2.json
+++ b/advisories/unreviewed/2026/04/GHSA-h383-gmxw-35v2/GHSA-h383-gmxw-35v2.json
@@ -1,19 +1,59 @@
 {
   "schema_version": "1.4.0",
   "id": "GHSA-h383-gmxw-35v2",
-  "modified": "2026-04-10T18:31:18Z",
+  "modified": "2026-04-10T18:31:27Z",
   "published": "2026-04-10T18:31:18Z",
   "aliases": [
     "CVE-2026-34479"
   ],
-  "details": "The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.\n\nTwo groups of users are affected:\n\n  *  Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file.\n  *  Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class.\n\n\nUsers are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.\n\nNote: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the  Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge.",
+  "summary": "Apache Log4j 1 to Log4j 2 bridge: silent log event loss in Log4j1XmlLayout due to unescaped XML 1.0 forbidden characters",
+  "details": "The `Log4j1XmlLayout` from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.\n\nTwo groups of users are affected:\n\n* Those using `Log4j1XmlLayout` directly in a Log4j Core 2 configuration file.\n* Those using the Log4j 1 configuration compatibility layer with `org.apache.log4j.xml.XMLLayout` specified as the layout class.\n\nUsers are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version `2.25.4`, which corrects this issue.\n\n> [!NOTE]\n> The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the\n[Log4j 1 to Log4j 2 migration guide](https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html), and specifically the section on eliminating reliance on the bridge.",
   "severity": [
     {
       "type": "CVSS_V4",
-      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
+      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N"
+    }
+  ],
+  "affected": [
+    {
+      "package": {
+        "ecosystem": "Maven",
+        "name": "org.apache.logging.log4j:log4j-1.2-api"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "2.7"
+            },
+            {
+              "fixed": "2.25.4"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "package": {
+        "ecosystem": "Maven",
+        "name": "org.apache.logging.log4j:log4j-1.2-api"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "3.0.0-beta1"
+            },
+            {
+              "last_affected": "3.0.0-beta2"
+            }
+          ]
+        }
+      ]
     }
   ],
-  "affected": [],
   "references": [
     {
       "type": "ADVISORY",
@@ -23,6 +63,10 @@
       "type": "WEB",
       "url": "https://github.com/apache/logging-log4j2/pull/4078"
     },
+    {
+      "type": "PACKAGE",
+      "url": "https://github.com/apache/logging-log4j2"
+    },
     {
       "type": "WEB",
       "url": "https://lists.apache.org/thread/gd0hp6mj17rn3kj279vgy4p7kd4zz5on"