CVE-2003-1564

Name: CVE-2003-1564
Creator: NVD / NIST
Published: 2003-12-31T05:00:00+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.62%

Last modified Jun 16, 2026

CVE-2003-1564 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. libxml2, possibly before 2.5.0, does not properly detect recursion during entity expansion, which allows context-dependent attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, aka the "billion laughs attack.". EPSS estimates a 1.62% chance of exploitation in the next 30 days.

Description

libxml2, possibly before 2.5.0, does not properly detect recursion during entity expansion, which allows context-dependent attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, aka the "billion laughs attack."

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS Probability

1.62%

73.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-776

Affected Software

Vendor	Product	Versions
Xmlsoft	Libxml2	< 2.5.0

References

http://mail.gnome.org/archives/xml/2008-August/msg00034.htmlMailing List, Patch
http://secunia.com/advisories/31868Broken Link
http://www.reddit.com/r/programming/comments/65843/time_to_upgrade_libxml2Issue Tracking
http://www.redhat.com/support/errata/RHSA-2008-0886.htmlBroken Link
http://www.stylusstudio.com/xmldev/200302/post20020.htmlBroken Link
http://xmlsoft.org/news.htmlRelease Notes
http://mail.gnome.org/archives/xml/2008-August/msg00034.htmlMailing List, Patch
http://secunia.com/advisories/31868Broken Link
http://www.reddit.com/r/programming/comments/65843/time_to_upgrade_libxml2Issue Tracking
http://www.redhat.com/support/errata/RHSA-2008-0886.htmlBroken Link
http://www.stylusstudio.com/xmldev/200302/post20020.htmlBroken Link
http://xmlsoft.org/news.htmlRelease Notes

Timeline

Published: Dec 31, 2003
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2003-1564?

How severe is CVE-2003-1564?

CVE-2003-1564 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.62% probability of exploitation in the next 30 days.

How do I fix CVE-2003-1564?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2003-1564?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST