CVE-2018-25079Public exploitNetwork attack vector

Service hang via catastrophic URL-regex backtracking

Published Feb 4, 2023 · Updated Aug 5, 2024

Regular expression denial of service in Segment is-url 1.2.2 and earlier allows remote attackers to hang consuming Node.js servers. The isUrl function tests untrusted strings against one alternation-heavy URL matcher whose localhost branch triggers catastrophic backtracking. Exposure requires a consuming server to pass remotely supplied URL text to the library; CPU exhaustion delays or hangs that process without data access or modification.

CVSS severity7.5
High
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in Segment is-url 1.2.2 and earlier allows remote attackers to hang consuming Node.js servers. The isUrl function tests untrusted strings against one alternation-heavy URL matcher whose localhost branch triggers catastrophic backtracking. Exposure requires a consuming server to pass remotely supplied URL text to the library; CPU exhaustion delays or hangs that process without data access or modification.

The record

CVE
CVE-2018-25079
Published
Feb 4, 2023
Updated
Aug 5, 2024
Vendor
Segment
Product
is-url
Classifications
CWE-1333, CAPEC-492, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record 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=1.2.0
  2. Affected versionversion=1.2.1
  3. Affected versionversion=1.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Segment · is-urlversion=1.2.0; version=1.2.1; version=1.2.2

Published CVSS scores

4.0VulDBAV:N/AC:L/Au:S/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
CAPEC-492Regular Expression Exponential Blowup
T1499.004Endpoint Denial of Service Application or System Exploitation

Public exploit references

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

Technologies

Your stack

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Your stack

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