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CVE-2016-1521

28
FAUCET Score

CVE-2016-1521 is a critical vulnerability in Libgraphite's directrun function, affecting Graphite 2 1.2.4, specifically as used in Mozilla Firefox before version 43.0 and Firefox ESR 38.x before 38.6.1, as well as Debian, Fedora, and SIL products. This flaw, an out-of-bounds read, allows remote attackers to execute arbitrary code, obtain sensitive information, or cause a denial of service via a crafted Graphite smart font. Rated with a CVSSv3 score of 8.8 (High), it requires user interaction (UI:R) but has a low attack complexity (AC:L) and network attack vector (AV:N), leading to high confidentiality, integrity, and availability impacts. Despite its severity, there is no evidence of active exploitation, publicly available exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
7.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
8.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
<= 1.2.4CPE matchmatch criteria
cpe:2.3:a:sil:graphite2:*:*:*:*:*:*:*:*
<= 42.0CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
38.0.1CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:38.0.1:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.0

8.8HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9
CvssVersion
3.0

Exploit Intelligence

EPSS Score
4.06%
Probability of exploitation in next 30 days
EPSS Percentile
89.6%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0406 is in the 89th percentile among its peer group of 14,825 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 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 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.1 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (7)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 5Fixed in: firefox-0:38.6.1-1.el5_11
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 5Fixed in: thunderbird-0:38.6.0-1.el5_11
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 6Fixed in: firefox-0:38.6.1-1.el6_7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 6Fixed in: thunderbird-0:38.6.0-1.el6_7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: firefox-0:38.6.1-1.el7_2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: thunderbird-0:38.6.0-1.el7_2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: graphite2-0:1.3.6-1.el7_2
View patch

Vendor Advisories (1)

redhatCVE-2016-1521Important

graphite2: Out-of-bound read vulnerability triggered by crafted fonts

Feb 5, 2016

References

blog.talosintel.com / 2016/02/vulnerability-spotlight-libgraphite.html
Third Party Advisory
lists.fedoraproject.org / pipermail/package-announce/2016-February/177520.html
Third Party Advisory
lists.fedoraproject.org / pipermail/package-announce/2016-May/184623.html
Third Party Advisory
lists.opensuse.org / opensuse-security-announce/2016-03/msg00052.html
lists.opensuse.org / opensuse-security-announce/2016-03/msg00058.html
lists.opensuse.org / opensuse-security-announce/2016-03/msg00088.html
rhn.redhat.com / errata/RHSA-2016-0197.html
rhn.redhat.com / errata/RHSA-2016-0258.html
rhn.redhat.com / errata/RHSA-2016-0594.html
h20566.www2.hpe.com / portal/site/hpsc/public/kb/docDisplay
security.gentoo.org / glsa/201701-35
security.gentoo.org / glsa/201701-63
debian.org / security/2016/dsa-3479
Third Party Advisory
mozilla.org / security/announce/2016/mfsa2016-14.html
Third Party Advisory
oracle.com / technetwork/topics/security/linuxbulletinapr2016-2952096.html
oracle.com / technetwork/topics/security/linuxbulletinjan2016-2867209.html
securityfocus.com / bid/82991
ubuntu.com / usn/USN-2902-1