PHPApplication
CVE-2015-8394
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedPCRE before 8.38 mishandles the (?(<digits>) and (?(R<digits>) conditions, which allows remote attackers to cause a denial of service (integer overflow) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencePCRE versions before 8.38 contain an integer overflow vulnerability when processing the (?(<digits>) and (?(R<digits>) conditional regex patterns. This can be triggered via specially crafted regular expressions (such as JavaScript RegExp objects), potentially causing denial of service or unspecified other impact.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
PHPApplication
>= 5.5.0, < 5.5.32>= 5.6.0, < 5.6.18>= 7.0.0, < 7.0.3<= 8.37CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine PCRE library versionRun `pcretest -v` or `pcre-config --version` to identify the installed PCRE library versionAffected if The version returned is 8.37 or earlier (8.00 through 8.37)
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Determine PHP versionRun `php -v` to identify the PHP interpreter versionAffected if The version is 5.5.0 through 5.5.31, 5.6.0 through 5.6.17, or 7.0.0 through 7.0.2
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Check PHP bundled PCRE versionRun `php -i` and search for the PCRE version line in the output, or create a PHP script containing `phpinfo();` and examine itAffected if The PCRE version shown is 8.37 or earlier and the PHP version falls within the affected ranges in step 2
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Identify applications using PCREFor non-PHP applications, search for binary dependencies that link to libpcre (on Linux: `ldd <executable>` | grep pcre, or `dpkg -l | grep pcre` / `rpm -qa | grep pcre`)Affected if The linked PCRE library version is 8.37 or earlier
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Check if application processes untrusted regexAudit application code for locations where user-controlled input is passed to regex functions (such as preg_match, preg_replace, or PCRE-based functions in other languages)Affected if The application processes regex patterns derived from untrusted sources and uses a vulnerable PCRE version
You are affected if your PCRE library version is 8.37 or earlier, or if your PHP version is 5.5.0-5.5.31, 5.6.0-5.6.17, or 7.0.0-7.0.2 with bundled PCRE 8.37 or earlier, and your application processes the vulnerable conditional regex patterns (?(<digits>) or (?(R<digits>).
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.5.325.6.187.0.3
Upgrade PCRE to version 8.38 or later. Identify and update all applications and libraries that depend on the vulnerable PCRE version to ensure complete remediation.
PHP 5.5.32+ / 5.6.18+ / 7.0.3+ or PCRE 8.38+
- Identify the current PHP version by running 'php -v' or 'phpinfo()'
- For PHP 5.5.x users: Upgrade to PHP 5.5.32 or later
- For PHP 5.6.x users: Upgrade to PHP 5.6.18 or later
- For PHP 7.0.x users: Upgrade to PHP 7.0.3 or later
- If using PCRE directly (not via PHP): Upgrade PCRE library to version 8.38 or later
- Verify the upgrade was successful by checking that PHP now uses PCRE 8.38 or later: 'php -i | grep -i pcre'
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in PHP
Scoped from the published advisory
- Consultation6.0 h
- Implementation4.0 h
- Testing10.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,624.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-8394 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2015-8394 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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