Medium

Memory leak in CSS::Minifier::XS minify

IdentifiersCVE-2026-13593CWE-401· Missing Release of Memory after…

CVE-2026-13593 affects CSS::Minifier::XS for Perl before version 0.14. The vulnerability is a memory leak in the minify function that occurs when processing input for which the entire document is removed during minification. Specifically, documents consisting only of removable characters, such as comments and whitespace, can trigger the leak. This results from memory not being properly released after processing this edge-case input.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful triggering of the flaw causes memory consumption to grow due to leaked allocations in the minify function. In applications that repeatedly process attacker-controlled or malformed CSS input, this can lead to resource exhaustion and potentially denial of service over time, particularly for long-running processes or services embedding the vulnerable Perl module.

Mitigation

If you can’t patch tonight, do this now.

If immediate upgrade is not possible, avoid passing untrusted or attacker-controlled CSS input to the vulnerable minify function, especially inputs composed entirely of comments, whitespace, or other characters that will be fully removed during minification. Operationally, reduce exposure by isolating the minification process, applying memory limits, and restarting long-lived worker processes to limit the impact of memory growth. However, no complete mitigation short of upgrading is provided in the available information.

Remediation

Patch, then assume compromise.

Upgrade CSS::Minifier::XS to version 0.14 or later, which contains the fix for the memory leak condition.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

ACTIVITY FEED

Recent activity

6 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.

6 SOURCESView more in app

No news coverage yet. Advisories and community discussion only.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity6

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-13593

NVD

nvd.nist.gov/vuln/detail/CVE-2026-13593

MITRE CWE · CWE-401

Missing Release of Memory after Effective…

openwall.com

openwall.com/lists/oss-security/2026/06/29/18

metacpan.org

metacpan.org/release/GTERMARS/CSS-Minifier-XS-0.14/changes

Memory leak in CSS::Minifier::XS minify

IdentifiersCVE-2026-13593CWE-401· Missing Release of Memory after…