Is CVE-2026-104895 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-104895 being exploited in the wild.

How severe is CVE-2026-104895?

High severity, with a CVSS score of 7.5, published 28 October 2026.

Which products and versions are affected?

FasterXML Jackson-Dataformat-Smile 2.9.0–2.18.11, 2.19.0–2.21.7, 2.22.0–2.22.3, 3.0.0–3.1.7, 3.2.0–3.2.3.

Is there a fix for CVE-2026-104895?

Yes: fixed in jackson-dataformat-smile 2.18.12, 2.21.8, 2.22.4, 3.1.8, 3.2.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-104895 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-104895?

Check whether you run FasterXML Jackson-Dataformat-Smile at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-104895: FasterXML Jackson Smile async parser integer overflow in raw binary allocation

CVE-2026-104895 · Severity: high · CVSS 7.5 · Published 2026-10-28

Jackson's asynchronous Smile parser, used to deserialize Smile-formatted data in applications (commonly in reactive web frameworks like Spring WebFlux), contains a denial-of-service vulnerability where crafted input can force gigabytes of memory allocation or crash the parsing thread. An attacker sending roughly ten malicious bytes to a service parsing Smile data can exhaust memory or trigger a crash, disrupting application availability.

Vendors: FasterXML.

Quick answers

Is CVE-2026-104895 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-104895 being exploited in the wild.
How severe is CVE-2026-104895?: High severity, with a CVSS score of 7.5, published 28 October 2026.
Which products and versions are affected?: FasterXML Jackson-Dataformat-Smile 2.9.0–2.18.11, 2.19.0–2.21.7, 2.22.0–2.22.3, 3.0.0–3.1.7, 3.2.0–3.2.3.
Is there a fix for CVE-2026-104895?: Yes: fixed in jackson-dataformat-smile 2.18.12, 2.21.8, 2.22.4, 3.1.8, 3.2.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-104895 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-104895?: Check whether you run FasterXML Jackson-Dataformat-Smile at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: jackson-dataformat-smile 2.18.12, 2.21.8, 2.22.4, 3.1.8, 3.2.4

Technical details

The NonBlockingByteArrayParser's _decodeVInt() method lacks an overflow guard when computing raw-binary lengths (missing the (value >>> 25) != 0 check present in the blocking parser), and _startRawBinary() eagerly allocates a byte[] of that length before reading the body. A crafted VInt on the 0xFD raw-binary marker either overflows to negative (triggering NegativeArraySizeException) or encodes a ~2 GB length, forcing immediate allocation that causes OutOfMemoryError. This escapes the parser contract as a non-JacksonException RuntimeException that is not caught by framework error handlers.

Affected products

FasterXML jackson-dataformat-smile 2.9.0–2.18.11, 2.19.0–2.21.7, 2.22.0–2.22.3, 3.0.0–3.1.7, 3.2.0–3.2.3

Timeline

2026-10-20: disclosed: GitHub security advisory GHSA-h3c2-2m49-r49w published
2026-10-28: advisory: CVE-2026-104895 published to NVD

References

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