Is CVE-2009-1955 in the CISA KEV catalog?

No. CVE-2009-1955 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2009-1955?

CVE-2009-1955 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2009-1955?

CVE-2009-1955 has an EPSS score of 52.99% (99th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2009-1955?

Upgrade apr-util on debian 11 to 1.3.7+dfsg-1 or later. Fixes are available for 2 affected products.

CVE & CISA-KEV Catalog

CVE-2009-1955

HIGHEPSS 99th pctl

7.5

CVSS v3

NVD

Description

The expat XML parser in the apr_xml_* interface in xml/apr_xml.c in Apache APR-util before 1.3.7, as used in the mod_dav and mod_dav_svn modules in the Apache HTTP Server, allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document containing a large number of nested entity references, as demonstrated by a PROPFIND request, a similar issue to CVE-2003-1564.

CWE-776

How to fix

Remediation Available

apr-utilDebian

Fixed in:1.3.7+dfsg-1CVE-2009-1955

httpdWindows application

Affected:2.2.0 2.2.12Fixed in:2.2.12Apache Lounge

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

52.99%probability of exploitation in 30 days

99thpercentile

Very high risk: more likely to be exploited than 99% of all known CVEs.

References

Related Vulnerabilities

Other CWE-776 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2017-18640	High	7.5	27%	-	Fix
CVE-2019-11253	High	7.5	26%	-	Fix
CVE-2019-12401	High	7.5	7.5%	-	-
CVE-2023-20052	Medium	5.3	7.0%	-	Fix
CVE-2019-15903	High	7.5	6.7%	-	Fix
CVE-2021-23926	Critical	9.1	6.2%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.