CVE-2017-9233

CVE-2017-9233 is a high-severity vulnerability in Libexpat Project Libexpat with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-611.

Key facts

Description

XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.

Frequently asked questions

What is CVE-2017-9233?
XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.
How severe is CVE-2017-9233?
CVE-2017-9233 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2017-9233 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-9233?
CVE-2017-9233 primarily affects Libexpat Project Libexpat. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-9233?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-9233 published?
CVE-2017-9233 was published on 2017-07-25 and last updated on 2026-06-17.

References

Affected products (5)

More vulnerabilities in Libexpat Project Libexpat

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Other CWE-611 (Improper Restriction of XML External Entity Reference (XXE)) vulnerabilities

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Threat intelligence

Threat-intel indicators referencing this CVE: