CVE & CISA-KEV Catalog

CVE-2015-6838

HIGHEPSS 94th pctl
7.5
CVSS v3
NVD

Description

The xsl_ext_function_php function in ext/xsl/xsltprocessor.c in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13, when libxml2 before 2.9.2 is used, does not consider the possibility of a NULL valuePop return value before proceeding with a free operation after the principal argument loop, which allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted XML document, a different vulnerability than CVE-2015-6837.

How to fix

Remediation Available
libapache2-mod-php5Ubuntu
Fixed in:5.5.9+dfsg-1ubuntu4.13USN-2758-1
php5Ubuntu
Fixed in:5.5.9+dfsg-1ubuntu4.13USN-2758-1
php5-cgiUbuntu
Fixed in:5.5.9+dfsg-1ubuntu4.13USN-2758-1
php5-cliUbuntu
Fixed in:5.5.9+dfsg-1ubuntu4.13USN-2758-1
php5-fpmUbuntu
Fixed in:5.5.9+dfsg-1ubuntu4.13USN-2758-1

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

Exploit Intelligence

7.28%probability of exploitation in 30 days
94thpercentile

High risk: more likely to be exploited than 94% of all known CVEs.

References

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Markdown

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HTML

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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 2026-05-06.