CVE-2025-11230Network attack vector

Process termination via unbounded exponent loop

Published Nov 19, 2025 · Updated Nov 19, 2025

Inefficient JSON parsing in affected HAProxy releases allows remote attackers to terminate the proxy process using large numeric exponents. The mjson number converter calculates an unbounded exponent with an O(exponent) iterative loop, consuming CPU until HAProxy's watchdog kills the process. Exposure requires json_query(), jwt_header_query(), or jwt_payload_query() in the configuration; repeated crafted requests interrupt proxied traffic.

CVSS severity7.5
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Inefficient JSON parsing in affected HAProxy releases allows remote attackers to terminate the proxy process using large numeric exponents. The mjson number converter calculates an unbounded exponent with an O(exponent) iterative loop, consuming CPU until HAProxy's watchdog kills the process. Exposure requires json_query(), jwt_header_query(), or jwt_payload_query() in the configuration; repeated crafted requests interrupt proxied traffic.

The record

CVE
CVE-2025-11230
Published
Nov 19, 2025
Updated
Nov 19, 2025
Vendor
HAProxy Technologies
Product
HAProxy
Classifications
CWE-407, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 19, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=2.4.0 <2.4.30
  2. Affected versionversion=2.6.0 <2.6.23
  3. Affected versionversion=2.8.0 <2.8.16
  4. Affected versionversion=3.0.0 <3.0.12
  5. Affected versionversion=3.1.0 <3.1.9
  6. Affected versionversion=3.2.0 <3.2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HAProxy Technologies · HAProxyversion=2.4.0 <2.4.30; version=2.6.0 <2.6.23; version=2.8.0 <2.8.16; version=3.0.0 <3.0.12; version=3.1.0 <3.1.9; version=3.2.0 <3.2.6

Published CVSS scores

7.5Canonical Ltd.CVSS: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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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