CVE-2026-119194
Description
A flaw was found in pyasn1. A remote attacker could trigger a Denial of Service (DoS) by sending specially crafted Abstract Syntax Notation One (ASN.1) data containing colliding tag identifiers during schemaless decoding. Processing these inputs causes inefficient container lookups that consume excessive CPU resources, leading to service degradation or unresponsiveness.
Statement
This vulnerability is rated as an Important impact because unauthenticated remote attackers can cause complete availability loss through CPU exhaustion against services processing untrusted ASN.1 data. The risk manifests when applications decode BER, CER, or DER structures without an explicit schema, allowing crafted colliding tag identifiers to induce quadratic computational overhead. Deployments where pyasn1 operations validate inputs against predefined schemas or operate exclusively on trusted internal data remain 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 | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | 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:L/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); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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