CVE-2026-13593Network attack vector

Service interruption via removable-only CSS memory leak

Published Jun 29, 2026 · Updated Jun 29, 2026

Memory leak in CSS::Minifier::XS before 0.14 allows context-dependent attackers to exhaust memory via removable-only CSS input. The minify() function fails to release allocated memory when it removes every input character, including comments and whitespace, and produces an empty document. Reachability requires a consuming application to pass attacker-controlled CSS to the library; repeated calls can exhaust process memory and interrupt that application.

CVSS severity6.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in CSS::Minifier::XS before 0.14 allows context-dependent attackers to exhaust memory via removable-only CSS input. The minify() function fails to release allocated memory when it removes every input character, including comments and whitespace, and produces an empty document. Reachability requires a consuming application to pass attacker-controlled CSS to the library; repeated calls can exhaust process memory and interrupt that application.

The record

CVE
CVE-2026-13593
Published
Jun 29, 2026
Updated
Jun 29, 2026
Vendor
Graham TerMarsch
Product
CSS::Minifier::XS
Classifications
CWE-401, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 2026Record 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 <0.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Graham TerMarsch · CSS::Minifier::XSversion=0 <0.14

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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 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-401Missing Release of Memory after Effective Lifetime
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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