CVE-2018-6340
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting...
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
- Record
CVE-2018-6340- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2018-18100
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
- Record
EUVD-2018-18100- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-q37v-wf54-qchq
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting...
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
- Record
GHSA-q37v-wf54-qchq- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-125
- Updated
- 2026-11-02
NVD
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
- Record
CVE-2018-6340- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-125
- Updated
- 2026-11-02
OSV
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
- Record
CVE-2018-6340- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-04
OSVUBUNTU-CVE-2018-6340
The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
- Record
UBUNTU-CVE-2018-6340- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
hhvmUbuntu:16.04:LTS |
All versions, plus listed versions 3.11.0+dfsg-13.11.1+dfsg-13.11.1+dfsg-1ubuntu1 |
None known |
hhvmUbuntu:18.04:LTS |
All versions, plus listed versions 3.21.0+dfsg-23.21.0+dfsg-2build13.21.0+dfsg-2build23.21.0+dfsg-2build33.21.0+dfsg-2ubuntu2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2018-6340 is a high vulnerability (CVSS 8.1) in Facebook Hhvm, published December 31, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.43%, the 73rd percentile. No source names a fixed version.