{"id":"CVE-2026-106554","title":"jackson-dataformat-cbor: quadratic-time TagList growth on unbounded stacked tags (CPU/GC DoS, PoC)","summary":"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).\n\n\n\nPoC executed against com.fasterxml.jackson.dataformat:jackson-…","severity":"none","cwe":["CWE-407"],"vendor":"FasterXML","product":"com.fasterxml.jackson.dataformat:jackson-dataformat-cbor","affected":["com.fasterxml.jackson.dataformat:jackson-dataformat-cbor >= 2.15.0 < 2.18.12","com.fasterxml.jackson.dataformat:jackson-dataformat-cbor >= 2.19.0 < 2.21.8","com.fasterxml.jackson.dataformat:jackson-dataformat-cbor >= 2.22.0 < 2.22.4","tools.jackson.dataformat:jackson-dataformat-cbor >= 3.0.0 < 3.1.8","tools.jackson.dataformat:jackson-dataformat-cbor >= 3.2.0 < 3.2.4"],"published":"2026-11-04","updated":"2026-11-04","sourceUpdated":"2026-11-04T16:14:05.664Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-106554","references":[{"url":"https://github.com/FasterXML/jackson-dataformats-binary/security/advisories/GHSA-cjg7-h3pr-p927","label":"GHSA-cjg7-h3pr-p927"}],"tags":["cve.org"],"ingestedAt":"2026-11-05T21:36:00.451Z","epss":0.00177,"epssPercentile":0.07345,"slug":"CVE-2026-106554","body":"## Overview\n\nOne 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).\n\n\n\nPoC 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.\n\n\n\nQuadratic CPU/GC DoS from an unbounded chain of CBOR tags (PoC-proven). File: cbor/src/main/java/.../cbor/CBORParser.java (tag handling -> TagList).\n\n\n\nCBOR 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.\n\n\n\nPoC (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.\n\n\n\nImpact. 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.\n\n\n\nFix. Grow TagList by doubling and/or cap the number of stacked tags (StreamReadConstraints-style).\n\n## Affected\n\n- `com.fasterxml.jackson.dataformat:jackson-dataformat-cbor >= 2.15.0 < 2.18.12`\n- `com.fasterxml.jackson.dataformat:jackson-dataformat-cbor >= 2.19.0 < 2.21.8`\n- `com.fasterxml.jackson.dataformat:jackson-dataformat-cbor >= 2.22.0 < 2.22.4`\n- `tools.jackson.dataformat:jackson-dataformat-cbor >= 3.0.0 < 3.1.8`\n- `tools.jackson.dataformat:jackson-dataformat-cbor >= 3.2.0 < 3.2.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}