CVE-2015-7575: Mozilla Network Security Services (NSS) before 3.20.2, as used in Mozilla Firefox before 43.0.2 and Firefox ES

Q: How do I fix CVE-2015-7575?

network security services: upgrade to newer than 3.20.1; leap: mitigate or apply the listed mitigation; opensuse: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2015-7575 being exploited?

CVE-2015-7575 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2015-7575 affect?

CVE-2015-7575 affects network security services, leap, opensuse. Severity is medium (CVSS 5.9). Mozilla Network Security Services (NSS) before 3.20.2, as used in Mozilla Firefox before 43.0.2 and Firefox ESR 38.x before 38.5.2, does not reject MD5 signatures in Server Key Exchange messages in TLS 1.2 Handshake Protocol traffic, which

Q: How urgent is CVE-2015-7575?

Priority 52/100. Remotely exploitable, no login, no user action; On your watchlist

This month

MEDIUM 5.9REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2015-7575 is a medium-severity flaw (CVSS 5.9) affecting network security services, leap, opensuse. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Mozilla Network Security Services (NSS) before 3.20.2, as used in Mozilla Firefox before 43.0.2 and Firefox ESR 38.x before 38.5.2, does not reject MD5 signatures in Server Key Exchange messages in TLS 1.2 Handshake Protocol traffic, which makes it easier for man-in-the-middle attackers to spoof servers by triggering a collision.

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	2.9% (top 13%)
CISA exploited list	No
Weakness	CWE-19
Published	2016-01-09
Last modified	2026-10-14

Publisher (CNA): Red Hat, Inc. · Vendor: canonical · mozilla · opensuse

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2016-01-09 02:59 UTCPublished CVE record published
2026-10-14 22:17 UTCUpdated Record last modified

mozilla network security services UPGRADE

Affected: <= 3.20.1

Fixed in: newer than 3.20.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy network-security-services || rpm -q network-security-services || network-security-services --version

2. UPGRADE to newer than 3.20.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade network-security-services

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade network-security-services

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

opensuse leap MITIGATE

Affected: 42.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 42.1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

opensuse opensuse MITIGATE

Affected: 13.1 · 13.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 13.1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

mozilla firefox UPGRADE

Affected: 38.0 · 38.0.1 · 38.0.5 · 38.1.0 · 38.1.1 · 38.2.0 · 38.2.1 · 38.3.0

Fixed in: newer than 43.0.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy firefox || rpm -q firefox || firefox --version

2. UPGRADE to newer than 43.0.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade firefox

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade firefox

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

canonical ubuntu linux MITIGATE

Affected: 14.04 · 15.04 · 15.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 14.04

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2015-7575?

network security services: upgrade to newer than 3.20.1; leap: mitigate or apply the listed mitigation; opensuse: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2015-7575 being exploited?

CVE-2015-7575 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2015-7575 affect?

CVE-2015-7575 affects network security services, leap, opensuse. Severity is medium (CVSS 5.9). Mozilla Network Security Services (NSS) before 3.20.2, as used in Mozilla Firefox before 43.0.2 and Firefox ESR 38.x before 38.5.2, does not reject MD5 signatures in Server Key Exchange messages in TLS 1.2 Handshake Protocol traffic, which

How urgent is CVE-2015-7575?

Priority 52/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Ubuntu vulnerabilities · Mozilla Firefox vulnerabilities

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References

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