How severe is CVE-2009-3560?

CVE-2009-3560 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-3560 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 24% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-3560?

CVE-2009-3560 primarily affects Libexpat Project Libexpat. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-3560?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-3560 published?

CVE-2009-3560 was published on 2009-12-04 and last updated on 2026-06-16.

CVE-2009-3560

CVE-2009-3560 is a medium-severity vulnerability in Libexpat Project Libexpat with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 24% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 24% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Libexpat Project Libexpat
Published: 2009-12-04
Last modified: 2026-06-16

Description

The big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with malformed UTF-8 sequences that trigger a buffer over-read, related to the doProlog function in lib/xmlparse.c, a different vulnerability than CVE-2009-2625 and CVE-2009-3720.

Frequently asked questions

What is CVE-2009-3560?: The big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with malformed UTF-8 sequences that trigger a buffer over-read, related to the doProlog function in lib/xmlparse.c, a different vulnerability than CVE-2009-2625 and CVE-2009-3720.
How severe is CVE-2009-3560?: CVE-2009-3560 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-3560 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 24% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3560?: CVE-2009-3560 primarily affects Libexpat Project Libexpat. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3560?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-3560 published?: CVE-2009-3560 was published on 2009-12-04 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:a:libexpat_project:libexpat:2.0.1:*:*:*:*:*:*:*
cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*

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Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

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CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

221.161.235.168 (ipv4-addr)
124.6.178.98 (ipv4-addr)
103.20.122.54 (ipv4-addr)
144.22.150.242 (ipv4-addr)
222.99.52.202 (ipv4-addr)
211.253.10.61 (ipv4-addr)
121.164.135.251 (ipv4-addr)
41.224.62.206 (ipv4-addr)