CVE-2026-106554: FasterXML jackson-dataformat-cbor quadratic-time tag parsing DoS

CVE-2026-106554 · Severity: info · Published 2026-11-04

Jackson's CBOR data parser is a library component used to deserialize binary messages in applications. An attacker can craft a malicious CBOR message with a long chain of semantic tags that forces the parser to consume quadratic amounts of CPU and garbage collection resources, stalling request processing threads and potentially denying service to legitimate users.

Vendors: FasterXML.

Quick answers

Is CVE-2026-106554 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-106554 being exploited in the wild.
How severe is CVE-2026-106554?
Informational severity, published 4 November 2026.
Which products and versions are affected?
FasterXML Jackson-Dataformat-Cbor 2.x and 3.x, including 2.18.2.
Is there a fix for CVE-2026-106554?
No fixed version is recorded yet. Applications using jackson-dataformat-cbor should restrict the maximum nesting depth of CBOR tags via StreamReadConstraints configuration to prevent excessive CPU and GC overhead from pathological inputs. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-106554 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-106554?
Check whether you run FasterXML Jackson-Dataformat-Cbor 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

Applications using jackson-dataformat-cbor should restrict the maximum nesting depth of CBOR tags via StreamReadConstraints configuration to prevent excessive CPU and GC overhead from pathological inputs.

Technical details

The jackson-dataformat-cbor CBOR parser accumulates semantic tags in a TagList with a fixed-increment growth strategy (+8 elements per expansion), causing O(N²) time complexity when parsing N nested tags due to repeated array copying and re-scanning. An attacker sends a CBOR stream with an unbounded chain of tag bytes (e.g., 0xC0+) before a simple value, exhausting CPU and triggering garbage collection pressure with no enforced limit on tag depth.

Affected products

  • FasterXML jackson-dataformat-cbor 2.x and 3.x, including 2.18.2

Timeline

  • 2026-11-04: disclosed

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