CVE-2014-3676: Heap-based buffer overflow in Shim allows remote attackers to execute arbitrary code via a crafted IPv6 addres

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HIGH 7.5WATCHLISTUPGRADE

CVE-2014-3676 is a high-severity flaw (CVSS 7.5) affecting shim. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Heap-based buffer overflow in Shim allows remote attackers to execute arbitrary code via a crafted IPv6 address, related to the "tftp:// DHCPv6 boot option."

Why this priority

High severity
EPSS top 7%: very likely to be exploited
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	5.2% (top 7%)
CISA exploited list	No
Weakness	CWE-787
Published	2014-10-22
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: redhat

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2014-10-22 14:55 UTCPublished CVE record published
2026-06-17 00:08 UTCUpdated Record last modified

redhat shim UPGRADE

Affected: >= 0.3 and < 0.8

Fixed in: 0.8

Safe to downgrade to: a release before 0.3

1. Check installed version

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

2. UPGRADE to 0.8 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade shim

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 0.3 (Debian / Ubuntu)

apt-cache madison shim sudo apt install shim=<VERSION_BEFORE_0.3> sudo apt-mark hold shim

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

dnf --showduplicates list shim sudo dnf downgrade shim-<VERSION_BEFORE_0.3> sudo dnf versionlock add shim

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-2014-3676?

shim: upgrade to 0.8. Exact commands for each OS are on this page.

Is CVE-2014-3676 being exploited?

CVE-2014-3676 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-2014-3676 affect?

CVE-2014-3676 affects shim. Severity is high (CVSS 7.5). Heap-based buffer overflow in Shim allows remote attackers to execute arbitrary code via a crafted IPv6 address, related to the "tftp:// DHCPv6 boot option."

How urgent is CVE-2014-3676?

Priority 59/100. High severity; EPSS top 7%: very likely to be exploited; Public exploit reference; On your watchlist

Related CVEs

CVE-2023-40548 HIGH 7.4 UPGRADE MITIGATE A buffer overflow was found in Shim in the 32-bit system
CVE-2023-40547 HIGH 8.3 UPGRADE MITIGATE A remote code execution vulnerability was found in Shim
CVE-2023-40551 MEDIUM 5.1 UPGRADE MITIGATE A flaw was found in the MZ binary format in Shim
CVE-2023-40550 MEDIUM 5.5 UPGRADE MITIGATE An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information
CVE-2023-40549 MEDIUM 6.2 UPGRADE MITIGATE An out-of-bounds read flaw was found in Shim due to the lack of proper boundary verification during the load o

References

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