HhvmApplication · Facebook

CVE-2019-11926

CRITICAL · 9.8 CVSS v3.0 Published 2019-09-06
Fix available
A fix is available. Upgrade to after 4.20.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

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
Insufficient boundary checks when processing M_SOFx markers from JPEG headers in the GD extension could allow access to out-of-bounds memory via a maliciously constructed invalid JPEG input. This issue affects HHVM versions prior to 3.30.9, all versions between 4.0.0 and 4.8.3, all versions between 4.9.0 and 4.15.2, and versions 4.16.0 to 4.16.3, 4.17.0 to 4.17.2, 4.18.0 to 4.18.1, 4.19.0, 4.20.0 to 4.20.1.

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
HhvmApplication
Affected:<= 3.30.9>= 4.0.0, <= 4.8.3>= 4.9.0, <= 4.15.2>= 4.16.0, <= 4.16.3>= 4.17.0, <= 4.17.2>= 4.18.0, <= 4.18.1>= 4.20.0, <= 4.20.1= 4.19.0

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 4.20.1
Vendor patch github.com →
Recommended fix High confidence

HHVM 4.21.0 or later (or HHVM 3.30.10+ if staying on 3.x branch)

  1. 1. Identify the current HHVM version in use: `hhvm --version`
  2. 2. Review the commit at https://github.com/facebook/hhvm/commit/f9680d21beaa9eb39d166e8810e29fbafa51ad15 for the specific code changes made to fix the boundary check vulnerability
  3. 3. If currently on HHVM 3.x series (≤3.30.9), upgrade to HHVM 3.30.10 or later
  4. 4. If currently on HHVM 4.x series (≤4.8.3, ≤4.15.2, ≤4.16.3, or within 4.17.x-4.20.x ranges), upgrade to HHVM 4.21.0 or later
  5. 5. Verify the upgrade by checking: `hhvm --version`
  6. 6. Test all JPEG processing functionality in applications using the GD extension to ensure proper operation
  7. 7. Monitor for any regression issues after upgrade
Caveat HHVM upgrades may introduce breaking changes in PHP compatibility or extension behavior; review HHVM release notes for the target version before upgrading

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-2019-11926 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
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  • Version or environment caveats, and links to real fixes
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