CVE-2018-12886: stack_protect_prologue in cfgexpand.c and stack_protect_epilogue in function.c in GNU Compiler Collection (GCC

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HIGH 8.1REMOTEUPGRADE

CVE-2018-12886 is a high-severity flaw (CVSS 8.1) affecting gcc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

stack_protect_prologue in cfgexpand.c and stack_protect_epilogue in function.c in GNU Compiler Collection (GCC) 4.1 through 8 (under certain circumstances) generate instruction sequences when targeting ARM targets that spill the address of the stack protector guard, which allows an attacker to bypass the protection of -fstack-protector, -fstack-protector-all, -fstack-protector-strong, and -fstack-protector-explicit against stack overflow by contr

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-209
Published	2019-05-22
Last modified	2026-10-14

Publisher (CNA): MITRE · Vendor: gnu

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

Am I affected?

Timeline

2019-05-22 19:29 UTCPublished CVE record published
2026-10-14 07:16 UTCUpdated Record last modified

gnu gcc UPGRADE

Affected: >= 4.1 and <= 8.0

Fixed in: newer than 8.0

Safe to downgrade to: a release before 4.1

1. Check installed version

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

2. UPGRADE to newer than 8.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gcc

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 4.1 (Debian / Ubuntu)

apt-cache madison gcc sudo apt install gcc=<VERSION_BEFORE_4.1> sudo apt-mark hold gcc

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

dnf --showduplicates list gcc sudo dnf downgrade gcc-<VERSION_BEFORE_4.1> sudo dnf versionlock add gcc

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-2018-12886?

gcc: upgrade to newer than 8.0. Exact commands for each OS are on this page.

Is CVE-2018-12886 being exploited?

CVE-2018-12886 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-2018-12886 affect?

CVE-2018-12886 affects gcc. Severity is high (CVSS 8.1). stack_protect_prologue in cfgexpand.c and stack_protect_epilogue in function.c in GNU Compiler Collection (GCC) 4.1 through 8 (under certain circumstances) generate instruction sequences when targeting ARM targets that spill the address of

How urgent is CVE-2018-12886?

Priority 60/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

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References

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