CVE-2026-61814Network attack vectorHinoki check available

CPU exhaustion via repeated incomplete-token rescanning

Published Sep 23, 2026 · Updated Sep 23, 2026

Algorithmic-complexity denial of service in Typelevel Jawn before 1.7.0 allows remote attackers to exhaust CPU via chunked JSON. AsyncParser's absorb method rescans an incomplete token from its beginning whenever another small chunk arrives, producing quadratic work. An application must use AsyncParser on untrusted JSON while the attacker controls large token content and chunk boundaries; the bounded impact is a service hang from CPU exhaustion.

CVSS severity7.5
High
EPSS probability0.57%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Algorithmic-complexity denial of service in Typelevel Jawn before 1.7.0 allows remote attackers to exhaust CPU via chunked JSON. AsyncParser's absorb method rescans an incomplete token from its beginning whenever another small chunk arrives, producing quadratic work. An application must use AsyncParser on untrusted JSON while the attacker controls large token content and chunk boundaries; the bounded impact is a service hang from CPU exhaustion.

The record

CVE
CVE-2026-61814
Published
Sep 23, 2026
Updated
Sep 23, 2026
Vendor
Typelevel
Product
Jawn Parser
Classifications
CWE-407, CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.7.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Typelevel · Jawn Parserversion=< 1.7.0
MVP Themes · Jawnversion=< 1.7.0

Published CVSS scores

7.5GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-407Inefficient Algorithmic Complexity
CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started