What is CVE-2017-5461?

CVE-2017-5461 is a critical-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2017-05-11.

How severe is CVE-2017-5461?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2017-5461 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Mozilla Firefox

CVE-2017-5461

Mozilla Network Security Services (NSS) before 3.21.4, 3.22.x through 3.28.x before 3.28.4, 3.29.x before 3.29.5, and 3.30.x before 3.30.1 allows remote attackers to cause a denial of service (out-of-bounds write) or possibly have unspecified other impact by leveraging incorrect base64 operations.

Vulnerability class: Buffer Overflow

Published 2017-05-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.047 (91.7th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 91.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.047 · newest: 0.047 · change: 0.000

Affected products

Mozilla Firefox — versions unspecified
Mozilla Firefox Esr — versions unspecified, unspecified
Mozilla Network Security Services
Mozilla Thunderbird — versions unspecified

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

getupcloud/openshift-clair-controller

References

security.gentoo.org/glsa/201705-04 (vendor-advisory, Third Party Advisory)
www.securityfocus.com/bid/98050 (VDB Entry, Third Party Advisory, vdb-entry)
access.redhat.com/errata/RHSA-2017:1103 (vendor-advisory, Patch)
www.debian.org/security/2017/dsa-3831 (vendor-advisory, Patch)
access.redhat.com/errata/RHSA-2017:1100 (vendor-advisory, Patch)
access.redhat.com/errata/RHSA-2017:1102 (vendor-advisory, Patch)
access.redhat.com/errata/RHSA-2017:1101 (vendor-advisory, Patch)
www.debian.org/security/2017/dsa-3872 (vendor-advisory, Patch)
www.securitytracker.com/id/1038320 (VDB Entry, Third Party Advisory, vdb-entry)
www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html (Patch)

Frequently asked questions

What is CVE-2017-5461?: CVE-2017-5461 is a critical-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2017-05-11.
How severe is CVE-2017-5461?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2017-5461 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.