{"id":"UBUNTU-CVE-2026-106554","details":"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 -\u003e 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 configurable limit. Impact. Algorithmic-complexity denial of service (CWE-407): a modest input of stacked tags consumes quadratic CPU/GC, pinning a request thread; concurrent requests exhaust the pool. Fix. Grow TagList by doubling and/or cap the number of stacked tags (StreamReadConstraints-style).","modified":"2026-11-05T11:45:35.119347470Z","published":"2026-11-04T00:00:00Z","upstream":["CVE-2026-106554"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-106554"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-106554"},{"type":"REPORT","url":"github.com/fasterxml/jackson-dataformats-binary"},{"type":"REPORT","url":"repo.maven.apache.org/maven2"}],"affected":[{"package":{"name":"jackson-dataformat-cbor","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/jackson-dataformat-cbor?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.4.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libjackson2-dataformat-cbor","binary_version":"2.4.3-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-106554.json"}},{"package":{"name":"jackson-dataformat-cbor","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/jackson-dataformat-cbor?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.8-1","2.7.8-2","2.7.8-3"],"ecosystem_specific":{"binaries":[{"binary_version":"2.7.8-3","binary_name":"libjackson2-dataformat-cbor"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-106554.json"}},{"package":{"name":"jackson-dataformat-cbor","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/jackson-dataformat-cbor?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.8-3"],"ecosystem_specific":{"binaries":[{"binary_version":"2.7.8-3","binary_name":"libjackson2-dataformat-cbor"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-106554.json"}},{"package":{"name":"jackson-dataformat-cbor","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/jackson-dataformat-cbor?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.8-3","2.7.8-4","2.7.8-5"],"ecosystem_specific":{"binaries":[{"binary_version":"2.7.8-5","binary_name":"libjackson2-dataformat-cbor"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-106554.json"}},{"package":{"name":"jackson-dataformat-cbor","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/jackson-dataformat-cbor?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.8-5"],"ecosystem_specific":{"binaries":[{"binary_version":"2.7.8-5","binary_name":"libjackson2-dataformat-cbor"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-106554.json"}},{"package":{"name":"jackson-dataformat-cbor","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/jackson-dataformat-cbor?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.8-5.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libjackson2-dataformat-cbor","binary_version":"2.7.8-5.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-106554.json"}},{"package":{"name":"jackson-dataformat-cbor","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/jackson-dataformat-cbor?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.8-5.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libjackson2-dataformat-cbor","binary_version":"2.7.8-5.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-106554.json"}}],"schema_version":"1.9.2","severity":[{"type":"Ubuntu","score":"medium"}]}