Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-91776 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability. Its CVSS base score is 7.5 (High).
Operationally, ranked at the 38th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-39 (Process Isolation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-85002
Vulnerability Data
TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type ID resolves to the same fallback…
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deserializer but is retained as its own key in the _deserializers map. That map has no configurable bound and lives for the lifetime of the type deserializer, so an attacker who can repeatedly supply fresh unknown type IDs causes monotonic memory retention across requests. The reporter observed 10,000 retained entries from 10,000 distinct unknown IDs, against a single entry for a control that repeated one unknown ID the same number of times, isolating attacker-controlled key cardinality from request volume. Exploitation requires an application that enables name-based polymorphism with a defaultImpl or equivalent fallback, accepts attacker-influenced type IDs, and reuses a long-lived ObjectMapper across requests. The fix stops caching fallback resolutions for unrecognized IDs and bounds both the number of cached entries and the length of a cacheable type ID.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Process isolation confines resource consumption to separate domains, reducing blast radius without stopping the root flaw.
SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.
SC-6 enforces explicit allocation limits on resources, structurally preventing the weakness from occurring.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.
A.8.6's monitoring, stress-testing, projections, tuning, demand-reduction steps (e.g. optimizing queries, deleting obsolete data, restricting non-critical bandwidth) and capacity planning directly stop most uncontrolled consumption from being exploitable by keeping resources within safe bounds; the bounded remainder is algorithmic flaws (e.g. infinite loops, uncontrolled recursion) that no amount of capacity planning can prevent from exhausting a resource when triggered.
Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.
Monitoring network service usage and applying controls to restrict access when necessary limits an attacker’s ability to consume excessive resources through unrestricted or unauthenticated service calls.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-400, a class-level weakness. Rules are authored against its narrower children: CWE-770.