CVE-2007-4556

CVE-2007-4556 is a medium-severity vulnerability in Opensymphony Xwork with a CVSS 2.0 base score of 6.8. Its EPSS exploit-prediction score of 26% places it in the 98th percentile, indicating an elevated likelihood of exploitation.

Key facts

Description

Struts support in OpenSymphony XWork before 1.2.3, and 2.x before 2.0.4, as used in WebWork and Apache Struts, recursively evaluates all input as an Object-Graph Navigation Language (OGNL) expression when altSyntax is enabled, which allows remote attackers to cause a denial of service (infinite loop) or execute arbitrary code via form input beginning with a "%{" sequence and ending with a "}" character.

Frequently asked questions

What is CVE-2007-4556?
Struts support in OpenSymphony XWork before 1.2.3, and 2.x before 2.0.4, as used in WebWork and Apache Struts, recursively evaluates all input as an Object-Graph Navigation Language (OGNL) expression when altSyntax is enabled, which allows remote attackers to cause a denial of service (infinite loop) or execute arbitrary code via form input beginning with a "%{" sequence and ending with a "}" character.
How severe is CVE-2007-4556?
CVE-2007-4556 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2007-4556 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2007-4556?
CVE-2007-4556 affects Opensymphony Xwork. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2007-4556?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2007-4556 published?
CVE-2007-4556 was published on 2007-08-28 and last updated on 2026-06-16.

References

Affected products (1)

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