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CVE-2019-3556

26
FAUCET Score

CVE-2019-3556 is a path traversal vulnerability in HHVM's "admin" server, affecting versions prior to 4.56.2 and several versions between 4.57.0 and 4.83.0. An authenticated attacker can exploit the 'dump-pcre-cache' handler to write arbitrary files on the filesystem where the HHVM user has write access, leading to high impact on integrity and availability. With a CVSS score of 8.1 (High), this vulnerability is easily exploitable over the network with low attack complexity. There is currently no public exploit code available, nor is there evidence of active exploitation or significant community discussion.

Impacted Technologies

VendorProductVersion(s)CPE
< 4.56.2CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*
>= 4.57.0, <= 4.78.0CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*
4.79.0CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:4.79.0:*:*:*:*:*:*:*
4.80.0CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:4.80.0:*:*:*:*:*:*:*
4.81.0CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:4.81.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.1HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.2
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.73%
Probability of exploitation in next 30 days
EPSS Percentile
75.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0173 is in the 73rd percentile among its peer group of 17,844 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

github_advisorypatch availablevia nvd_reference
View patch

References

github.com / facebook/hhvm/commit/abe0b29e4d3a610f9bc920b8be4ad8403364c2d4
PatchThird Party Advisory
hhvm.com / blog/2020/11/12/security-update.html
Vendor Advisory
facebook.com / security/advisories/cve-2019-3556
Broken Link