CVE-2023-48631Network attack vector

Denial of service via inefficient parser regex

Published Dec 14, 2023 · Updated Aug 2, 2024

Regular expression denial of service in @adobe/css-tools 4.3.1 and earlier allows remote attackers to interrupt CSS parsing. The parser's selector and @custom-media expressions apply inefficient or insufficiently constrained regular-expression matching to crafted nested parentheses and whitespace, consuming excessive CPU. Crafted CSS can interrupt processing in a consuming application that passes attacker-controlled styles to the parser; no privileges or user interaction are required.

CVSS severity5.3
Medium
EPSS probability1.12%
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 @adobe/css-tools 4.3.1 and earlier allows remote attackers to interrupt CSS parsing. The parser's selector and @custom-media expressions apply inefficient or insufficiently constrained regular-expression matching to crafted nested parentheses and whitespace, consuming excessive CPU. Crafted CSS can interrupt processing in a consuming application that passes attacker-controlled styles to the parser; no privileges or user interaction are required.

The record

CVE
CVE-2023-48631
Published
Dec 14, 2023
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L
5.3Adobe Systems IncorporatedCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NIST National Vulnerability DatabaseCVSS: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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

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

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Your stack

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