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CVE-2019-3878

26
FAUCET Score

CVE-2019-3878 is a high-severity authentication bypass vulnerability affecting mod_auth_mellon versions prior to 0.14.2, specifically impacting configurations where Apache acts as a reverse proxy requiring authenticated users. An attacker can bypass authentication by sending specially crafted HTTP headers typically used for SAML ECP, leading to full compromise of confidentiality, integrity, and availability. While the CVSS score is 8.1 (HIGH) with a low EPSS score, there is no evidence of active exploitation, public exploit code, or significant community discussion.

Impacted Technologies

VendorProductVersion(s)CPE
< 0.14.2CPE matchmatch criteria
cpe:2.3:a:mod_auth_mellon_project:mod_auth_mellon:*:*:*:*:*:apache:*:*
29CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*
30CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
7.0CPE matchmatch criteria
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
7.0CPE matchmatch criteria
cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.0

8.1HIGH

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
2.8
Impact Score
5.2
CvssVersion
3.0

Exploit Intelligence

EPSS Score
2.97%
Probability of exploitation in next 30 days
EPSS Percentile
85.8%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0297 is in the 44th percentile among its peer group of 8,920 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 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 (13)

github_advisorypatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: mod_auth_mellon-0:0.14.0-2.el7_6.4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: mod_auth_mellon-0:0.14.0-3.el8_0.2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 6Fixed in: httpd24-httpd-0:2.4.34-7.el6.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: httpd24-httpd-0:2.4.34-7.el7.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: httpd24-mod_auth_mellon-0:0.13.1-2.el7.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUSFixed in: httpd24-httpd-0:2.4.34-7.el7.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUSFixed in: httpd24-mod_auth_mellon-0:0.13.1-2.el7.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUSFixed in: httpd24-httpd-0:2.4.34-7.el7.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUSFixed in: httpd24-mod_auth_mellon-0:0.13.1-2.el7.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUSFixed in: httpd24-httpd-0:2.4.34-7.el7.1
View patch
redhatpatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUSFixed in: httpd24-mod_auth_mellon-0:0.13.1-2.el7.1
View patch

Vendor Advisories (1)

redhatCVE-2019-3878Important

mod_auth_mellon: authentication bypass in ECP flow

May 10, 2018

References

access.redhat.com / errata/RHBA-2019:0959
access.redhat.com / errata/RHSA-2019:0746
Third Party Advisory
access.redhat.com / errata/RHSA-2019:0766
Third Party Advisory
access.redhat.com / errata/RHSA-2019:0985
bugzilla.redhat.com / show_bug.cgi
Issue TrackingPatchThird Party Advisory
github.com / Uninett/mod_auth_mellon/pull/196
ExploitPatchThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/CNW5YMC5TLWVWNJEY6AIWNSNPRAMWPQJ
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/X7NLAU7KROWNTHAYSA2S67X347F42L2I
usn.ubuntu.com / 3924-1
Third Party Advisory