One CBOR-parsing issue in jackson-dataformats-binary's CBOR module: an unbounded run of CBOR tags drives quadratic-time TagList growth…
CVE-2026-106554
One CBOR-parsing issue in jackson-dataformats-binary's CBOR module: an unbounded run of CBOR tags drives quadratic-time TagList growth (CPU/GC-exhaustion DoS, PoC-proven). PoC executed against com.fasterxml.jackson.dataformat:jackson-dataformat-cbor:2.18.2; present in current 2.x and 3.x (tools.jackson.dataformat.cbor) HEAD. Distinct from the Avro and Smile/Protobuf advisories for this repo. Quadratic CPU/GC DoS from an unbounded chain of CBOR tags (PoC-proven). File: cbor/src/main/java/.../cbor/CBORParser.java (tag handling -> TagList). CBOR permits a data item to be preceded by any number of semantic tags. The CBOR parser accumulates them in a TagList whose backing array grows by a fixed increment (+8), not by doubling, and re-scans/copies on each growth. An attacker sends a value preceded by a long run of tag bytes; the fixed-increment growth makes accumulating N tags O(N^2) in time (plus GC pressure), with no cap on the number of stacked tags. PoC (executed, JDK 17): feeding a CBOR stream consisting of a long run of tag bytes (e.g. tag 0xC0+) before a trivial value forces quadratic CPU/GC; parse time grows super-linearly with the tag count, pinning a request thread with no…
Assessment
- CVSS
- Not yet scored
- Severity
- Unscored
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 4 November 2026
- Last updated
- 4 November 2026
- Affected
- FasterXML · jackson-dataformat-cbor
- Assigner
- HeroDevs
At the source
References
Community proofs of concept
No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.
Submit a proof of concept
Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.
Query this programmatically
Agents can read this through the MCP endpoint, or over HTTP:
curl https://cve.zerocrew.in/api/cve/CVE-2026-106554