diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32ee5ca..367804f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,38 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Security
+
+- **Jackson bumped from 2.17.0 to 2.22.1**, and `jackson-core` is now declared
+  explicitly instead of being inherited transitively from `jackson-databind`.
+  Consumers of the SDK previously picked up `jackson-core:2.17.0` and
+  `jackson-databind:2.17.0` on their compile classpath.
+
+  This clears seven advisories that matched the old pin: on `jackson-core`,
+  GHSA-r7wm-3cxj-wff9 (High) and GHSA-72hv-8253-57qq (Moderate), both
+  `maxNumberLength` bypasses in the **non-blocking (async) parser**; on
+  `jackson-databind`, CVE-2026-54512 and CVE-2026-54513 (both High,
+  `PolymorphicTypeValidator` allowlist bypasses) plus CVE-2026-54514,
+  CVE-2026-54515 and CVE-2026-59888 (Moderate).
+
+  **The SDK itself did not reach any of these code paths.** It never constructs
+  a `JsonFactory` or an async parser (all JSON goes through `ObjectMapper`
+  blocking reads), and it never enables polymorphic typing, which is the
+  precondition for the `PolymorphicTypeValidator` bypasses. The bump matters
+  because the vulnerable jars land on the *consumer's* classpath, where the
+  same Jackson may be used by application code that does reach them.
+
+  No behavioural change: `@JsonInclude(NON_NULL)` omission, `Instant`
+  ISO-8601 rendering and parsing (including nanosecond precision), untyped
+  `Map<String, Object>` number-type inference, unknown-property tolerance and
+  `StreamReadConstraints` defaults were all compared across the two versions
+  and are byte-for-byte identical. Jackson's Java 8 bytecode baseline is
+  unchanged, so the SDK's Java 11 target is unaffected.
+
+  One transitive dependency disappears from the compile classpath as a
+  side-effect: `jackson-databind` 2.17.0 depended on `net.bytebuddy:byte-buddy`
+  and 2.22.1 does not.
+
 ## [9.0.0] - 2026-07-18
 
 ### Changed (BREAKING)
diff --git a/pom.xml b/pom.xml
index 6eaa825..6f4ade4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -51,7 +51,12 @@
 
         <!-- Dependency Versions -->
         <okhttp.version>4.12.0</okhttp.version>
-        <jackson.version>2.17.0</jackson.version>
+        <!-- Keep the whole Jackson family on one version. jackson-core is the
+             artifact that carries the async-parser advisories (GHSA-72hv-8253-57qq,
+             GHSA-r7wm-3cxj-wff9), and it reaches consumers transitively via
+             jackson-databind, so it is declared explicitly below rather than
+             being left to whatever databind happens to depend on. -->
+        <jackson.version>2.22.1</jackson.version>
         <slf4j.version>2.0.12</slf4j.version>
         <caffeine.version>3.1.8</caffeine.version>
 
@@ -96,6 +101,14 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson.version}</version>
         </dependency>
+        <!-- Declared explicitly (rather than inherited transitively from
+             jackson-databind) so the published POM states a floor on the
+             artifact that actually carries the advisories. -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-jsr310</artifactId>