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PcreApplication

CVE-2016-3191

CRITICAL · 9.8 CVSS v3.0 Published 2016-03-17
Fix available
A fix is available. Upgrade to after 10.21 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

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 · unedited
The compile_branch function in pcre_compile.c in PCRE 8.x before 8.39 and pcre2_compile.c in PCRE2 before 10.22 mishandles patterns containing an (*ACCEPT) substring in conjunction with nested parentheses, which allows remote attackers to execute arbitrary code or cause a denial of service (stack-based buffer overflow) via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror, aka ZDI-CAN-3542.

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
How this class of weakness works · CWE-119

The program reads or writes outside the bounds of an allocated buffer, corrupting adjacent memory. With crafted input an attacker can overwrite control data and, with effort, redirect execution to their own code. Remediation ranges from bounds checking and safe library functions to compiler mitigations, usually alongside a careful audit of the surrounding code.

General guidance for the memory buffer bounds error class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
PcreApplication
Affected:= 8.00= 8.01= 8.02= 8.10= 8.11= 8.12= 8.13= 8.20= 8.21= 8.30= 8.31= 8.32
Pcre2Application
Affected:<= 10.21

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

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 · scoped
Upgrade available Upgrade to a release after 10.21
Recommended fix High confidence

PCRE 8.x → 8.39 or later; PCRE2 → 10.22 or later

  1. Identify whether the system uses PCRE (8.x) or PCRE2 by checking the installed version (e.g., `pcre-config --version` or `pcre2-config --version`)
  2. If using PCRE 8.x: upgrade to version 8.39 or later (e.g., `yum update pcre` or `apt-get install libpcre3` depending on OS)
  3. If using PCRE2: upgrade to version 10.22 or later (e.g., `yum update pcre2` or `apt-get install libpcre2-8` depending on OS)
  4. After upgrading, restart any services that use PCRE to load the fixed library version
  5. Verify the installed version is at least 8.39 (for PCRE) or 10.22 (for PCRE2) using `pcre-config --version` or `pcre2-config --version`
Caveat Major OS upgrades may be required to obtain fixed PCRE packages on some distributions; custom builds should be rebuilt from source using the fixed versions

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-3191 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data