diff --git a/CHANGELOG.md b/CHANGELOG.md
index 52e7aed38..dd5e5c99b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,7 @@ All notable changes to this project will be documented in this file.
 - hbase: replace `sed` calls with `config-utils template` where possible ([#1301]).
 - superset: Fix the 4.1.2 build when building from source ([#1309])
 - superset: Pin `luxon` to version 3.6.1 to fix build ([#1315], [#1316])
+- nifi: Use a patched version of logback to fix corrupted logs ([#1314])
 
 ### Fixed
 
@@ -107,6 +108,7 @@ All notable changes to this project will be documented in this file.
 [#1308]: https://github.com/stackabletech/docker-images/pull/1308
 [#1309]: https://github.com/stackabletech/docker-images/pull/1309
 [#1311]: https://github.com/stackabletech/docker-images/pull/1311
+[#1314]: https://github.com/stackabletech/docker-images/pull/1314
 [#1315]: https://github.com/stackabletech/docker-images/pull/1315
 [#1316]: https://github.com/stackabletech/docker-images/pull/1316
 
diff --git a/nifi/Dockerfile b/nifi/Dockerfile
index 462f66afd..5235a8b4e 100644
--- a/nifi/Dockerfile
+++ b/nifi/Dockerfile
@@ -5,6 +5,8 @@ ARG GIT_SYNC_VERSION
 
 FROM oci.stackable.tech/sdp/git-sync/git-sync:${GIT_SYNC_VERSION} AS git-sync-image
 
+FROM local-image/shared/logback AS patched-logback
+
 FROM local-image/java-devel AS nifi-builder
 
 ARG PRODUCT_VERSION
@@ -23,8 +25,12 @@ WORKDIR /stackable
 COPY --chown=${STACKABLE_USER_UID}:0 nifi/stackable/patches/patchable.toml /stackable/src/nifi/stackable/patches/patchable.toml
 COPY --chown=${STACKABLE_USER_UID}:0 nifi/stackable/patches/${PRODUCT_VERSION} /stackable/src/nifi/stackable/patches/${PRODUCT_VERSION}
 COPY --chown=${STACKABLE_USER_UID}:0 --from=git-sync-image /git-sync /stackable/git-sync
+COPY --chown=${STACKABLE_USER_UID}:0 --from=patched-logback /stackable/.m2/repository /stackable/patched-logback-libs
 
 RUN <<EOF
+mkdir -p /stackable/.m2/repository
+cp -r /stackable/patched-logback-libs/* /stackable/.m2/repository
+
 # This used to be located in /bin/stackable-bcrypt.jar. We create a softlink for /bin/stackable-bcrypt.jar in the main container for backwards compatibility.
 curl 'https://repo.stackable.tech/repository/m2/tech/stackable/nifi/stackable-bcrypt/1.0-SNAPSHOT/stackable-bcrypt-1.0-20240508.153334-1-jar-with-dependencies.jar' \
     -o /stackable/stackable-bcrypt.jar
@@ -185,6 +191,7 @@ COPY --chown=${STACKABLE_USER_UID}:0 --from=nifi-iceberg-bundle-builder /stackab
 COPY --chown=${STACKABLE_USER_UID}:0 --from=nifi-iceberg-bundle-builder /stackable/*.cdx.json /stackable/nifi-${PRODUCT_VERSION}-stackable${RELEASE_VERSION}/lib/
 COPY --chown=${STACKABLE_USER_UID}:0 --from=nifi-iceberg-bundle-builder /stackable/*-src.tar.gz /stackable
 COPY --chown=${STACKABLE_USER_UID}:0 --from=nifi-builder /stackable/git-sync /stackable/git-sync
+COPY --chown=${STACKABLE_USER_UID}:0 --from=patched-logback /stackable/*-src.tar.gz /stackable
 
 COPY --chown=${STACKABLE_USER_UID}:0 --from=opa-authorizer-builder /stackable/opa-authorizer.nar /stackable/nifi-${PRODUCT_VERSION}-stackable${RELEASE_VERSION}/extensions/opa-authorizer.nar
 COPY --chown=${STACKABLE_USER_UID}:0 --from=opa-authorizer-builder /stackable/nifi-opa-plugin-${NIFI_OPA_AUTHORIZER_PLUGIN_VERSION}-src.tar.gz  /stackable
diff --git a/nifi/boil-config.toml b/nifi/boil-config.toml
index c20f96d8f..1181a68a4 100644
--- a/nifi/boil-config.toml
+++ b/nifi/boil-config.toml
@@ -1,6 +1,7 @@
 [versions."1.27.0".local-images]
 java-base = "11"
 java-devel = "11"
+"shared/logback" = "1.3.14"
 
 [versions."1.27.0".build-arguments]
 git-sync-version = "v4.4.1"
@@ -11,6 +12,7 @@ nifi-opa-authorizer-plugin-version = "0.3.0"
 [versions."1.28.1".local-images]
 java-base = "11"
 java-devel = "11"
+"shared/logback" = "1.3.14"
 
 [versions."1.28.1".build-arguments]
 git-sync-version = "v4.4.1"
@@ -21,6 +23,7 @@ nifi-opa-authorizer-plugin-version = "0.3.0"
 [versions."2.4.0".local-images]
 java-base = "21"
 java-devel = "21"
+"shared/logback" = "1.5.18"
 
 [versions."2.4.0".build-arguments]
 git-sync-version = "v4.4.1"
@@ -34,6 +37,7 @@ nifi-iceberg-bundle-version = "0.0.5"
 [versions."2.6.0".local-images]
 java-base = "21"
 java-devel = "21"
+"shared/logback" = "1.5.18"
 
 [versions."2.6.0".build-arguments]
 git-sync-version = "v4.4.1"
diff --git a/nifi/stackable/patches/2.6.0/0005-fix-pin-esbuild-to-fix-NiFi-2.6.0-build.patch b/nifi/stackable/patches/2.6.0/0005-fix-pin-esbuild-to-fix-NiFi-2.6.0-build.patch
new file mode 100644
index 000000000..548a2e55c
--- /dev/null
+++ b/nifi/stackable/patches/2.6.0/0005-fix-pin-esbuild-to-fix-NiFi-2.6.0-build.patch
@@ -0,0 +1,28 @@
+From 1fe22dcc974b52d83b8288d5279c3aa8c41a1243 Mon Sep 17 00:00:00 2001
+From: dervoeti <lukas.krug@stackable.tech>
+Date: Wed, 22 Oct 2025 15:27:29 +0200
+Subject: fix: pin esbuild to fix NiFi 2.6.0 build
+
+For some reason, npm tries to use a newer version of esbuild than the version in the lock file. I suspect this might be related to how npm handles optional dependencies in lock files. The esbuild version is set to 0.25.10 now to prevent npm from trying to select a newer version, so that the same packages as in the original NiFi build are used.
+---
+ nifi-frontend/src/main/frontend/package.json | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+diff --git a/nifi-frontend/src/main/frontend/package.json b/nifi-frontend/src/main/frontend/package.json
+index ee125e7663..6914c5f00c 100644
+--- a/nifi-frontend/src/main/frontend/package.json
++++ b/nifi-frontend/src/main/frontend/package.json
+@@ -114,10 +114,11 @@
+         "vite": "^5.4.6",
+         "underscore": "1.13.6",
+         "rollup": "4.22.4",
+-        "esbuild": "^0.25.8",
++        "esbuild": "0.25.10",
+         "koa": "^2.16.1"
+     },
+     "overrides": {
+-        "koa": "^2.16.1"
++        "koa": "^2.16.1",
++        "esbuild": "0.25.10"
+     }
+ }
diff --git a/shared/logback/Dockerfile b/shared/logback/Dockerfile
new file mode 100644
index 000000000..8fcd8b03a
--- /dev/null
+++ b/shared/logback/Dockerfile
@@ -0,0 +1,23 @@
+# syntax=docker/dockerfile:1.15.1@sha256:9857836c9ee4268391bb5b09f9f157f3c91bb15821bb77969642813b0d00518d
+# check=error=true
+
+FROM local-image/java-devel AS builder
+
+ARG PRODUCT_VERSION
+ARG RELEASE_VERSION
+ARG STACKABLE_USER_UID
+
+COPY --chown=${STACKABLE_USER_UID}:0 shared/logback/stackable/patches/patchable.toml /stackable/src/shared/logback/stackable/patches/patchable.toml
+COPY --chown=${STACKABLE_USER_UID}:0 shared/logback/stackable/patches/${PRODUCT_VERSION} /stackable/src/shared/logback/stackable/patches/${PRODUCT_VERSION}
+
+USER ${STACKABLE_USER_UID}
+WORKDIR /stackable
+
+RUN <<EOF
+cd "$(/stackable/patchable --images-repo-root=src checkout shared/logback ${PRODUCT_VERSION})"
+
+# Create snapshot of the source code including custom patches
+tar -czf /stackable/logback-${PRODUCT_VERSION}-src.tar.gz .
+
+mvn --batch-mode --no-transfer-progress clean install -DskipTests -Dmaven.test.skip=true -Dmaven.javadoc.skip=true
+EOF
diff --git a/shared/logback/boil-config.toml b/shared/logback/boil-config.toml
new file mode 100644
index 000000000..206d0206e
--- /dev/null
+++ b/shared/logback/boil-config.toml
@@ -0,0 +1,5 @@
+[versions."1.3.14".local-images]
+java-devel = "21"
+
+[versions."1.5.18".local-images]
+java-devel = "21"
diff --git a/shared/logback/stackable/patches/1.3.14/0001-fix-move-StringBuilder-into-function-to-prevent-race.patch b/shared/logback/stackable/patches/1.3.14/0001-fix-move-StringBuilder-into-function-to-prevent-race.patch
new file mode 100644
index 000000000..0d7ec50e1
--- /dev/null
+++ b/shared/logback/stackable/patches/1.3.14/0001-fix-move-StringBuilder-into-function-to-prevent-race.patch
@@ -0,0 +1,38 @@
+From 2ee74eaf5645576ec0a604941591c9ae09a92a43 Mon Sep 17 00:00:00 2001
+From: dervoeti <lukas.krug@stackable.tech>
+Date: Wed, 22 Oct 2025 11:13:02 +0200
+Subject: fix: move StringBuilder into function to prevent race conditions
+
+---
+ .../java/ch/qos/logback/classic/log4j/XMLLayout.java   | 10 +---------
+ 1 file changed, 1 insertion(+), 9 deletions(-)
+
+diff --git a/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java b/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java
+index 4bc04388a..405f4ef26 100644
+--- a/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java
++++ b/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java
+@@ -38,9 +38,7 @@ import ch.qos.logback.core.helpers.Transform;
+ public class XMLLayout extends LayoutBase<ILoggingEvent> {
+ 
+     private final int DEFAULT_SIZE = 256;
+-    private final int UPPER_LIMIT = 2048;
+ 
+-    private StringBuilder buf = new StringBuilder(DEFAULT_SIZE);
+     private boolean locationInfo = false;
+     private boolean properties = false;
+ 
+@@ -96,13 +94,7 @@ public class XMLLayout extends LayoutBase<ILoggingEvent> {
+      */
+     public String doLayout(ILoggingEvent event) {
+ 
+-        // Reset working buffer. If the buffer is too large, then we need a new
+-        // one in order to avoid the penalty of creating a large array.
+-        if (buf.capacity() > UPPER_LIMIT) {
+-            buf = new StringBuilder(DEFAULT_SIZE);
+-        } else {
+-            buf.setLength(0);
+-        }
++        StringBuilder buf = new StringBuilder(DEFAULT_SIZE);
+ 
+         // We yield to the \r\n heresy.
+ 
diff --git a/shared/logback/stackable/patches/1.3.14/patchable.toml b/shared/logback/stackable/patches/1.3.14/patchable.toml
new file mode 100644
index 000000000..a33d0f790
--- /dev/null
+++ b/shared/logback/stackable/patches/1.3.14/patchable.toml
@@ -0,0 +1,2 @@
+mirror = "https://github.com/stackabletech/logback.git"
+base = "39fc5461e7a8e15ce9ecd9f148f67f701aed88ad"
diff --git a/shared/logback/stackable/patches/1.5.18/0001-fix-move-StringBuilder-into-function-to-prevent-race.patch b/shared/logback/stackable/patches/1.5.18/0001-fix-move-StringBuilder-into-function-to-prevent-race.patch
new file mode 100644
index 000000000..18ac0cc90
--- /dev/null
+++ b/shared/logback/stackable/patches/1.5.18/0001-fix-move-StringBuilder-into-function-to-prevent-race.patch
@@ -0,0 +1,38 @@
+From 174aa552f3f1fc03dcce3b37f24993b77b90ab71 Mon Sep 17 00:00:00 2001
+From: dervoeti <lukas.krug@stackable.tech>
+Date: Fri, 17 Oct 2025 12:07:51 +0200
+Subject: fix: move StringBuilder into function to prevent race conditions
+
+---
+ .../java/ch/qos/logback/classic/log4j/XMLLayout.java   | 10 +---------
+ 1 file changed, 1 insertion(+), 9 deletions(-)
+
+diff --git a/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java b/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java
+index 4bc04388a..405f4ef26 100644
+--- a/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java
++++ b/logback-classic/src/main/java/ch/qos/logback/classic/log4j/XMLLayout.java
+@@ -38,9 +38,7 @@ import ch.qos.logback.core.helpers.Transform;
+ public class XMLLayout extends LayoutBase<ILoggingEvent> {
+ 
+     private final int DEFAULT_SIZE = 256;
+-    private final int UPPER_LIMIT = 2048;
+ 
+-    private StringBuilder buf = new StringBuilder(DEFAULT_SIZE);
+     private boolean locationInfo = false;
+     private boolean properties = false;
+ 
+@@ -96,13 +94,7 @@ public class XMLLayout extends LayoutBase<ILoggingEvent> {
+      */
+     public String doLayout(ILoggingEvent event) {
+ 
+-        // Reset working buffer. If the buffer is too large, then we need a new
+-        // one in order to avoid the penalty of creating a large array.
+-        if (buf.capacity() > UPPER_LIMIT) {
+-            buf = new StringBuilder(DEFAULT_SIZE);
+-        } else {
+-            buf.setLength(0);
+-        }
++        StringBuilder buf = new StringBuilder(DEFAULT_SIZE);
+ 
+         // We yield to the \r\n heresy.
+ 
diff --git a/shared/logback/stackable/patches/1.5.18/patchable.toml b/shared/logback/stackable/patches/1.5.18/patchable.toml
new file mode 100644
index 000000000..01153d924
--- /dev/null
+++ b/shared/logback/stackable/patches/1.5.18/patchable.toml
@@ -0,0 +1,2 @@
+mirror = "https://github.com/stackabletech/logback.git"
+base = "b2a02f065379a9b1ba5ff837fc08913b744774bc"
diff --git a/shared/logback/stackable/patches/patchable.toml b/shared/logback/stackable/patches/patchable.toml
new file mode 100644
index 000000000..fb98269ec
--- /dev/null
+++ b/shared/logback/stackable/patches/patchable.toml
@@ -0,0 +1,2 @@
+upstream = "https://github.com/qos-ch/logback.git"
+default-mirror = "https://github.com/stackabletech/logback.git"