CVE-2026-89407
Description
A flaw was found in jackson-core. An attacker can supply specially crafted JSON that, when deserialized into a numeric target type, triggers a Regular expression Denial of Service (ReDoS) vulnerability. This occurs due to quadratic backtracking in the NumberInput.looksLikeValidNumber() method's PATTERN_FLOAT regular expression. A small number of concurrent requests with a long input string can exhaust a server's request-handling thread pool, leading to a Denial of Service (DoS).
Statement
This vulnerability is rated as Moderate impact because while remote actors can induce CPU starvation to trigger a denial of service, the issue affects availability only without granting unauthorized access or data tampering capabilities. In Red Hat environments, exposure depends on services deserializing untrusted JSON payloads into numeric Java object types where default string coercion occurs. Older releases packaging jackson-core versions prior to 2.17.0 do not include the vulnerable pattern matching logic and are unaffected.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Attackers can create crafted inputs that intentionally cause the regular expression to use excessive backtracking in a way that causes the CPU consumption to spike.
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