Upstream information
Description
The fix released in jackson-core 2.18.6 and 2.21.1 for CVE-2026-18401 (GHSA-72hv-8253-57qq, number length constraint bypass in the non-blocking parser) is incomplete. This record covers the remaining bypass.The earlier fix wired validateIntegerLength() into a new _setIntLength() helper and invoked it wherever the integer portion of a number is decided: a terminator byte arrives, a '.' or 'e'/'E' is seen, or input ends inside a fully buffered value. It was not invoked on the attacker-relevant path where the parser runs out of input while still inside the MINOR_NUMBER_INTEGER_DIGITS minor state and returns NOT_AVAILABLE to the caller.
As a result, an attacker who streams JSON to a non-blocking parser in many small chunks, without ever sending a terminator byte, keeps the parser inside MINOR_NUMBER_INTEGER_DIGITS indefinitely. _textBuffer.expandCurrentSegment() grows the accumulator on every chunk while validateIntegerLength() is never called. The accumulator is bounded only by maxStringLength (20 MiB by default) rather than by maxNumberLength (1000 by default), an amplification of roughly 20,000x over the documented limit. Because Java char values occupy two bytes, a single connection can be driven to approximately 40 MiB of heap before the validator finally fires when the value completes.
The equivalent fraction-path code is correct: _finishFloatFraction() calls _setFractLength() before its NOT_AVAILABLE return. The missing call affects the integer-digit paths in _startPositiveNumber(), _startNegativeNumber() and _finishNumberIntegralPart() in NonBlockingUtf8JsonParserBase.
Impact: reactive frameworks such as Spring WebFlux/Reactor, Quarkus, Helidon and Vert.x feed inbound HTTP or gRPC bytes to the async parser as they arrive, which is precisely the chunked-feed shape required. Operators who set StreamReadConstraints.maxNumberLength expecting it to cap memory per number value do not get that guarantee; memory accumulates per concurrent connection and attacker-controlled concurrency can exhaust the JVM heap. The synchronous parsers (UTF8StreamJsonParser, ReaderBasedJsonParser) and the async parser operating on complete input are not affected.
Exploitation requires only the ability to stream data to a parsing endpoint; no privileges or user interaction are needed.
This issue affects com.fasterxml.jackson.core:jackson-core from version 2.15.0 through 2.18.7, and from 2.19.0 through 2.21.3, and tools.jackson.core:jackson-core from 3.0.0 through 3.1.3. Versions prior to 2.15.0 are not affected, because StreamReadConstraints -- which defines the maxNumberLength setting -- was first introduced in jackson-core 2.15.0, so no such constraint exists to be bypassed in earlier releases. Note that GHSA-r7wm-3cxj-wff9 states the affected 2.x range without a lower bound. The 2.22.x and 3.2.x release lines are not affected: those branches were created after the fix commit landed on 2026-05-21 and therefore contain it from their initial releases (2.22.0, tagged 2026-06-03, and 3.2.0, tagged 2026-06-08).
SUSE information
Overall state of this security issue: Resolved
This issue is currently rated as having important severity.
| CVSS detail | SUSE |
|---|---|
| Base Score | 7.5 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | High |
| CVSSv3 Version | 3.1 |
| CVSS detail | CNA (HeroDevs) | SUSE |
|---|---|---|
| Base Score | 8.7 | 8.7 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| Attack Vector | Network | Network |
| Attack Complexity | Low | Low |
| Attack Requirements | None | None |
| Privileges Required | None | None |
| User Interaction | None | None |
| Vulnerable System Confidentiality Impact | None | None |
| Vulnerable System Integrity Impact | None | None |
| Vulnerable System Availability Impact | High | High |
| Subsequent System Confidentiality Impact | None | None |
| Subsequent System Integrity Impact | None | None |
| Subsequent System Availability Impact | None | None |
| CVSSv4 Version | 4.0 | 4.0 |
Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP7 | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | jackson-core | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP7 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 16.0 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 16.1 | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | jackson-core | Not affected |
| openSUSE Leap 16.0 | jackson-core | Not affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP4 | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | jackson-core | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | jackson-core | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP4 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP5 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP6 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | jackson-core | Not affected |
| SUSE Manager Proxy 4.3 | jackson-core | Not affected |
| SUSE Manager Proxy LTS 4.3 | jackson-core | Not affected |
| SUSE Manager Retail Branch Server 4.3 | jackson-core | Not affected |
| SUSE Manager Retail Branch Server LTS 4.3 | jackson-core | Not affected |
| SUSE Manager Server 4.3 | jackson-core | Not affected |
| SUSE Manager Server LTS 4.3 | jackson-core | Not affected |
| SUSE Manager Server Module 4.3 | jackson-core | Not affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE Enterprise Storage 7 | jackson-core | Not affected |
| SUSE Enterprise Storage 7.1 | jackson-core | Not affected |
| SUSE Linux Enterprise Desktop 15 SP2 | jackson-core | Not affected |
| SUSE Linux Enterprise Desktop 15 SP3 | jackson-core | Not affected |
| SUSE Linux Enterprise Desktop 15 SP4 | jackson-core | Not affected |
| SUSE Linux Enterprise Desktop 15 SP5 | jackson-core | Not affected |
| SUSE Linux Enterprise Desktop 15 SP6 | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | jackson-core | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | jackson-core | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | jackson-core | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | jackson-core | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | jackson-core | Not affected |
| SUSE Linux Enterprise Real Time 15 SP2 | jackson-core | Not affected |
| SUSE Linux Enterprise Real Time 15 SP3 | jackson-core | Not affected |
| SUSE Linux Enterprise Real Time 15 SP4 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP2 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP3 | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | jackson-core | Not affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | jackson-core | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | jackson-core | Not affected |
| SUSE Manager Proxy 4.1 | jackson-core | Not affected |
| SUSE Manager Proxy 4.2 | jackson-core | Not affected |
| SUSE Manager Retail Branch Server 4.1 | jackson-core | Not affected |
| SUSE Manager Retail Branch Server 4.2 | jackson-core | Not affected |
| SUSE Manager Server 4.1 | jackson-core | Not affected |
| SUSE Manager Server 4.2 | jackson-core | Not affected |
| openSUSE Leap 15.3 | jackson-core | Not affected |
| openSUSE Leap 15.4 | jackson-core | Not affected |
| openSUSE Leap 15.5 | jackson-core | Not affected |
| openSUSE Leap 15.6 | jackson-core | Not affected |
| Container Status | ||
| suse/manager/5.0/x86_64/server suse/manager/5.0/x86_64/server-attestation suse/multi-linux-manager/5.1/x86_64/server suse/multi-linux-manager/5.1/x86_64/server-attestation suse/multi-linux-manager/5.2/x86_64/server suse/multi-linux-manager/5.2/x86_64/server-attestation | jackson-core | Not affected |
SUSE Timeline for this CVE
CVE page created: Wed Aug 5 15:41:38 2026CVE page last modified: Wed Aug 5 15:41:38 2026