CVE-2022-25758Network attack vector

Application hang via greedy source-map regex

Published Jul 1, 2022 · Updated Sep 17, 2024

Regular expression denial of service in sasstools scss-tokenizer before 0.4.3 allows remote attackers to hang consuming applications. In src/previous-map.js, loadAnnotation() applies a greedy capture to untrusted CSS while locating a sourceMappingURL comment, causing excessive backtracking on crafted input. Exploitation requires a consuming application to pass attacker-controlled CSS to the tokenizer; the resulting CPU exhaustion interrupts that application without disclosed data access or modification.

CVSS severity7.5
High
EPSS probability2.08%
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 sasstools scss-tokenizer before 0.4.3 allows remote attackers to hang consuming applications. In src/previous-map.js, loadAnnotation() applies a greedy capture to untrusted CSS while locating a sourceMappingURL comment, causing excessive backtracking on crafted input. Exploitation requires a consuming application to pass attacker-controlled CSS to the tokenizer; the resulting CPU exhaustion interrupts that application without disclosed data access or modification.

The record

CVE
CVE-2022-25758
Published
Jul 1, 2022
Updated
Sep 17, 2024
Vendor
sasstools
Product
scss-tokenizer
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 1, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=0 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

sasstools · scss-tokenizerversion=0 <unspecified

Published CVSS scores

7.5GitHub Advisory 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.

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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-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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