Disclosure summary
## Summary The fix released in jackson-core `2.18.6` and `2.21.1` for [GHSA-72hv-8253-57qq](https://github.com/FasterXML/jackson-core/security/advisories/GHSA-72hv-8253-57qq) (Number Length Constraint Bypass in Async Parser, published 2026-02-28) is incomplete. The fix commit `b0c428e6` (#1555) wired `validateIntegerLength` into a new `_setIntLength` helper and called it at every place where the integer portion of a number is *decided* (terminator byte arrived, `.` / `e/E` seen, end-of-feed inside a fully-buffered value). It did not call it on the much more attacker-relevant path: "ran out of input while still inside `MINOR_NUMBER_INTEGER_DIGITS`, return `NOT_AVAILABLE` to caller". As a result, an attacker who streams JSON to a non-blocking parser in many small chunks, without ever sending a terminator byte, can keep the parser inside `MINOR_NUMBER_INTEGER_DIGITS` indefinitely. `_textBuffer.expandCurrentSegment()` grows on every chunk, and `validateIntegerLength` is never invoked. The accumulator is only gated by `maxStringLength` (20 MiB default) — a **~20,000x amplification** of the documented `maxNumberLength` (1000 default). This is the same vulnerability class, same advisory w
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-r7wm-3cxj-wff9
Open original source · Updated Oct 02, 2026
jackson-core: Async parser maxNumberLength bypass via chunked digit accumulation (incomplete fix for GHSA-72hv-8253-57qq)
Source severity: HIGH / 8.7
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| maven | com.fasterxml.jackson.core:jackson-core | < 2.18.8 | 2.18.8 |
| maven | com.fasterxml.jackson.core:jackson-core | >= 2.19.0, < 2.21.4 | 2.21.4 |
| maven | tools.jackson.core:jackson-core | >= 3.0.0, < 3.1.4 | 3.1.4 |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Reviewed advisory
PUBLISHED 2026-07-21T17:58:53-04:00
MODIFIED 2026-10-02T19:08:42-04:00
INGESTED 2026-10-06T11:45:17-04:00