CVE-2026-68498 — jackson-core: Delayed maxNameLength enforcement for char-backed input (ReaderBasedJsonParser) allows memory-exhaustion denial of service
StreamReadConstraints.maxNameLength (default 50,000 characters) is intended to bound how much memory a single JSON Object property name can consume while being parsed, independently of the much larger maxStringLength (default 100,000,000 characters) that bounds ordinary string values. For parsers built over character input — Reader, String or char[] sources, all served by ReaderBasedJsonParser — that bound is not applied while the name is being accumulated. The code path instead re-uses the string-value length check, which is roughly 2000x larger by default. In the character-input slow path, ReaderBasedJsonParser._parseName2() accumulates the name into the TextBuffer and, when a segment fills, calls TextBuffer.finishCurrentSegment(), which validates only maxStringLength. The correct check, StreamReadConstraints.validateNameLength(int), is reached afterwards in CharsToNameCanonicalizer.findSymbol(), once the entire name has been scanned to its closing quote. By that point the full name — up to maxStringLength characters — has already been buffered in memory. A remote attacker who can have a single sufficiently long JSON Object property name parsed through this path can force allocation on the order of 100,000,000 characters (approximately 200 MB, with segment bookkeeping pushing real peak usage higher) before any StreamConstraintsException is thrown, instead of the approximately 50,000-character (about 100 KB) bound the API promises. Repeating this across concurrent requests can exhaust the heap and crash the process. No authentication or user interaction is required. Because StreamReadConstraints.maxDocumentLength is disabled by default (-1), nothing else bounds the token first, so the issue is exploitable under default configuration. Byte-input parsers are not affected: UTF8StreamJsonParser, UTF8DataInputJsonParser and the non-blocking (async) parsers re-validate maxNameLength on every growth of the name-decode buffer via ParserBase._growNameDecodeBuffer(), rejecting an oversized name after allocating only tens of kilobytes. Applications are exposed when untrusted JSON is parsed from a String, Reader or char[] — for example an HTTP request body already read into a String — rather than from raw UTF-8 bytes. This issue affects com.fasterxml.jackson.core:jackson-core from 2.16.0 and tools.jackson.core:jackson-core from 3.0.0. Releases before 2.16.0 are not affected, because StreamReadConstraints.maxNameLength was first introduced in jackson-core 2.16.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Fasterxml Jackson-core).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Fasterxml | Jackson-core | ≥ 2.16.0 and < 2.18.10≥ 2.19.0 and < 2.21.6≥ 2.22.0 and < 2.22.2≥ 3.0.0 and < 3.1.6≥ 3.2.0 and < 3.2.2 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | 36c7be3b-2937-45df-85ea-ca7133ea542c via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | — | — | HeroDevs via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: 36c7be3b-2937-45df-85ea-ca7133ea542c) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Source status changed · Published → Received
- Record published
- CVSS changed · 7.5
- Source status changed · → Published
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 16, 2026 – Oct 16, 2026
References
5 on the record
- github.com/FasterXML/jackson-core/commit/2cd206de1163e3fcff7bdaca425274f00668b07
- github.com/FasterXML/jackson-core/pull/1643
- github.com/FasterXML/jackson-core/blob/2.x/release-notes/VERSION-2.x
- github.com/FasterXML/jackson-core/security/advisories/GHSA-649p-m576-vr99
- github.com/FasterXML/jackson-core/blob/3.x/release-notes/VERSION
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-89425 jackson-core: UTF8DataInputJsonParser._reportInvalidToken() does not honor maxErrorTokenLength, allowing unbounded StringBuilder growth 25d
- High CVE-2026-89407 jackson-core: quadratic backtracking in NumberInput.PATTERN_FLOAT via looksLikeValidNumber() enables ReDoS 25d
- High CVE-2026-68494 jackson-core: Async parser maxNumberLength bypass via chunked digit accumulation (incomplete fix for CVE-2026-18401 / GHSA-72hv-8253-57qq) Aug 4, 2026
- Medium CVE-2026-18401 jackson-core: Number length constraint bypass in non-blocking (async) JSON parser leads to potential denial of service Aug 4, 2026
- High CVE-2026-29062 jackson-core: Nesting Depth Constraint Bypass in `UTF8DataInputJsonParser` potentially allowing Resource Exhaustion Mar 6, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-68498 is "jackson-core: Delayed maxNameLength enforcement for char-backed input (ReaderBasedJsonParser) allows memory-exhaustion denial of service", rated High. It affects Jackson-core (Fasterxml); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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