CVE-2016-6870
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order...
CVE-2016-6870 is a critical vulnerability (CVSS 9.8) in Facebook Hhvm, published February 17, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.21%, the 82nd percentile. No source names a fixed version.
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order functions in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order functions in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors.
- Record
CVE-2016-6870- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-787
- Updated
- 2026-11-02
CVE List No score
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order functions in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors.
- Record
CVE-2016-6870- Updated
- 2026-11-02
EUVDEUVD-2016-7755 No score
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order functions in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors.
- Record
EUVD-2016-7755- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-392p-w329-wxhf
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order...
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order functions in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors.
- Record
GHSA-392p-w329-wxhf- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order functions in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors.
- Record
CVE-2016-6870- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
OSVUBUNTU-CVE-2016-6870
Out-of-bounds write in the (1) mb_detect_encoding, (2) mb_send_mail, and (3) mb_detect_order functions in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors.
- Record
UBUNTU-CVE-2016-6870- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/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 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
openwall.com/lists/oss-security/2016/08/11/1
github.com/facebook/hhvm/commit/365abe807cab2d60dc9ec307292a06181f77a9c2
nvd.nist.gov/vuln/detail/CVE-2016-6870
ubuntu.com/security/CVE-2016-6870
cve.org/CVERecord?id=CVE-2016-6870