CVE-2020-10543: Perl before 5.30.3 on 32-bit platforms allows a heap-based buffer overflow because nested regular expression q

This week

HIGH 8.2REMOTEUPGRADEMITIGATEMITIGATE

CVE-2020-10543 is a high-severity flaw (CVSS 8.2) affecting perl, fedora, leap. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Perl before 5.30.3 on 32-bit platforms allows a heap-based buffer overflow because nested regular expression quantifiers have an integer overflow.

Why this priority

High severity
EPSS top 4%: very likely to be exploited
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	11.3% (top 4%)
CISA exploited list	No
Weakness	CWE-190, CWE-787
Published	2020-06-05
Last modified	2026-10-14

Publisher (CNA): MITRE · Vendor: fedoraproject · opensuse · oracle · perl

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

Am I affected?

Timeline

2020-06-05 14:15 UTCPublished CVE record published
2026-10-14 09:17 UTCUpdated Record last modified

perl perl UPGRADE

Affected: < 5.30.3

Fixed in: 5.30.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 5.30.3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade perl

Note

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

fedoraproject fedora MITIGATE

Affected: 31

Fixed in: no fixed release known

Safe to downgrade to: a release before 31

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 leap MITIGATE

Affected: 15.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.1

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.

oracle communications billing and revenue management DOWNGRADE

Affected: 12.0.0.2.0 · 12.0.0.3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.0.0.2.0

1. Check installed version

apt-cache policy communications-billing-and-revenue-management || rpm -q communications-billing-and-revenue-management || communications-billing-and-revenue-management --version

2. No fixed release: DOWNGRADE to a release before 12.0.0.2.0 (Debian / Ubuntu)

apt-cache madison communications-billing-and-revenue-management sudo apt install communications-billing-and-revenue-management=<VERSION_BEFORE_12.0.0.2.0> sudo apt-mark hold communications-billing-and-revenue-management

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list communications-billing-and-revenue-management sudo dnf downgrade communications-billing-and-revenue-management-<VERSION_BEFORE_12.0.0.2.0> sudo dnf versionlock add communications-billing-and-revenue-management

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

oracle communications diameter signaling router UPGRADE

Affected: >= 8.0.0 and <= 8.5.0

Fixed in: newer than 8.5.0

Safe to downgrade to: a release before 8.0.0

1. Check installed version

apt-cache policy communications-diameter-signaling-router || rpm -q communications-diameter-signaling-router || communications-diameter-signaling-router --version

2. UPGRADE to newer than 8.5.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade communications-diameter-signaling-router

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade communications-diameter-signaling-router

Note

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

3. If no update is available yet, DOWNGRADE to a release before 8.0.0 (Debian / Ubuntu)

apt-cache madison communications-diameter-signaling-router sudo apt install communications-diameter-signaling-router=<VERSION_BEFORE_8.0.0> sudo apt-mark hold communications-diameter-signaling-router

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list communications-diameter-signaling-router sudo dnf downgrade communications-diameter-signaling-router-<VERSION_BEFORE_8.0.0> sudo dnf versionlock add communications-diameter-signaling-router

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

oracle communications eagle application processor UPGRADE

Affected: >= 16.1.0 and <= 16.4.0

Fixed in: newer than 16.4.0

Safe to downgrade to: a release before 16.1.0

1. Check installed version

apt-cache policy communications-eagle-application-processor || rpm -q communications-eagle-application-processor || communications-eagle-application-processor --version

2. UPGRADE to newer than 16.4.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade communications-eagle-application-processor

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade communications-eagle-application-processor

Note

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

3. If no update is available yet, DOWNGRADE to a release before 16.1.0 (Debian / Ubuntu)

apt-cache madison communications-eagle-application-processor sudo apt install communications-eagle-application-processor=<VERSION_BEFORE_16.1.0> sudo apt-mark hold communications-eagle-application-processor

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list communications-eagle-application-processor sudo dnf downgrade communications-eagle-application-processor-<VERSION_BEFORE_16.1.0> sudo dnf versionlock add communications-eagle-application-processor

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2020-10543?

perl: upgrade to 5.30.3; fedora: mitigate or apply the listed mitigation; leap: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-10543 being exploited?

CVE-2020-10543 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-2020-10543 affect?

CVE-2020-10543 affects perl, fedora, leap. Severity is high (CVSS 8.2). Perl before 5.30.3 on 32-bit platforms allows a heap-based buffer overflow because nested regular expression quantifiers have an integer overflow.

How urgent is CVE-2020-10543?

Priority 58/100. High severity; EPSS top 4%: very likely to be exploited; Remotely exploitable, no login, no user action

Software pages

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References

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