CVE-2025-49128
MEDIUMCVE-2025-49128 is a medium-severity (CVSS 4) CWE-209 vulnerability in com.fasterxml.jackson.core:jackson-core. O3 Security confirms whether CVE-2025-49128 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Jackson-core Vulnerable to Memory Disclosure via Source Snippet in JsonLocation
Blast Radius
com.fasterxml.jackson.core:jackson-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Jackson-core contains core low-level incremental ("streaming") parser and generator abstractions used by Jackson Data Processor. Starting in version 2.0.0 and prior to version 2.13.0, a flaw in jackson-core's JsonLocation._appendSourceDesc method allows up to 500 bytes of unintended memory content to be included in exception messages. When parsing JSON from a byte array with an offset and length, the exception message incorrectly reads from the beginning of the array instead of the logical payload start. This results in possible information disclosure in systems using pooled or reused buffers, like Netty or Vert.x. This issue was silently fixed in jackson-core version 2.13.0, released on September 30, 2021, via PR #652. All users should upgrade to version 2.13.0 or later. If upgrading is not immediately possible, applications can mitigate the issue by disabling exception message exposure to clients to avoid returning parsing exception messages in HTTP responses and/or disabling source inclusion in exceptions to prevent Jackson from embedding any source content in exception messages, avoiding leakage.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.fasterxml.jackson.core:jackson-core | ≥ 2.0.0&&< 2.13.0 | 2.13.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.fasterxml.jackson.core:jackson-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update com.fasterxml.jackson.core:jackson-core to 2.13.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49128 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-49128 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-49128. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-49128 in your dependencies?
O3 detects CVE-2025-49128 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.