CVE-2015-6837: php
Vulnerability summary
CVE-2015-6837 is a high (CVSS 7.5) vulnerability in php. EPSS estimates a 7.35% chance of exploitation in the next 30 days, higher than 94.4% of scored vulnerabilities.
Severe, CVSS 7.5 (NVD); no exploitation reported by the 5 checked sources; EPSS 7% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 9 · Related 5Timeline
- 16-05-2016PublishedVulnerability first disclosed.
- 06-08-2024Last modifiedVulnerability information updated.
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 during initial error checking, 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-2015-6838.
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
7.35%
Chance of exploitation in the next 30 days
Percentile
94%
Versus all other CVEs
30-day change
No change 0.00 pp
From 7.35% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Php1 product
- phpEOL5.6.0:alpha1 | 5.6.0:alpha2 | 5.6.0:alpha3 | 5.6.0:alpha4 | 5.6.0:alpha5 | 5.6.0:beta1 | 5.6.0:beta2 | 5.6.0:beta3 | 5.6.0:beta4 | 5.6.1 | 5.6.2 | 5.6.3 | 5.6.4 | 5.6.5 | 5.6.6 | 5.6.7 | 5.6.8 | 5.6.9 | 5.6.10 | 5.6.11 | 5.6.12 | ≤ 5.4.44 | 5.5.0 | 5.5.0:alpha1 | 5.5.0:alpha2 | 5.5.0:alpha3 | 5.5.0:alpha4 | 5.5.0:alpha5 | 5.5.0:alpha6 | 5.5.0:beta1 | 5.5.0:beta2 | 5.5.0:beta3 | 5.5.0:beta4 | 5.5.0:rc1 | 5.5.0:rc2 | 5.5.1 | 5.5.2 | 5.5.3 | 5.5.4 | 5.5.5 | 5.5.6 | 5.5.7 | 5.5.8 | 5.5.9 | 5.5.10 | 5.5.11 | 5.5.12 | 5.5.13 | 5.5.14 | 5.5.15 | 5.5.16 | 5.5.17 | 5.5.18 | 5.5.19 | 5.5.20 | 5.5.21 | 5.5.22 | 5.5.23 | 5.5.24 | 5.5.25 | 5.5.26 | 5.5.27 | 5.5.28
Ubuntu1 product
- php5< 5.5.9+dfsg-1ubuntu4.13
Xmlsoft1 product
- libxml2≤ 2.9.1
3 vendors · 3 products
References
10 links- bugs.php.net/bug.php?id=69782X Refsource CONFIRM
- php.net/ChangeLog-5.phpX Refsource CONFIRM