PHPApplication
CVE-2017-9226
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 · uneditedAn issue was discovered in Oniguruma 6.2.0, as used in Oniguruma-mod in Ruby through 2.4.1 and mbstring in PHP through 7.1.5. A heap out-of-bounds write or read occurs in next_state_val() during regular expression compilation. Octal numbers larger than 0xff are not handled correctly in fetch_token() and fetch_token_in_cc(). A malformed regular expression containing an octal number in the form of '\700' would produce an invalid code point value larger than 0xff in next_state_val(), resulting in an out-of-bounds write memory corruption.
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 analysisThe program writes past the bounds of a buffer, overwriting adjacent memory an attacker can turn to their advantage. Crafted input can overwrite control data and redirect execution. Remediation is validating every index and length before a write, plus modern memory-safety mitigations.
General guidance for the out-of-bounds write 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
PHPApplication
< 5.6.31>= 7.0.0, < 7.0.21>= 7.1.0, < 7.1.7= 6.2.0CVSS 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
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 · scoped5.6.317.0.217.1.7
PHP 5.6.31, 7.0.21, or 7.1.7 (or later stable releases); Oniguruma 6.2.0 with commit b4bf968ad52afe14e60a2dc8a95d3555c543353a applied
- For PHP users: Upgrade PHP to version 5.6.31, 7.0.21, 7.1.7, or a later stable version that includes the fix
- For standalone Oniguruma users: Apply the patch from commit b4bf968ad52afe14e60a2dc8a95d3555c543353a (https://github.com/kkos/oniguruma/commit/b4bf968ad52afe14e60a2dc8a95d3555c543353a)
- After upgrading or patching, verify that the Oniguruma library version is 6.2.0 with the fix applied
- Test that PHP applications using regular expressions with octal sequences (e.g., '\700') no longer cause memory corruption
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-9226 — 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-2017-9226 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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- Version or environment caveats, and links to real fixes
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