CVE-2023-27705: APNG_Optimizer v1.4 was discovered to contain a buffer overflow via the component /apngopt/ubuntu.png.

This week

HIGH 7.5REMOTEWATCHLISTDOWNGRADE

CVE-2023-27705 is a high-severity flaw (CVSS 7.5) affecting apng optimizer. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

APNG_Optimizer v1.4 was discovered to contain a buffer overflow via the component /apngopt/ubuntu.png.

Why this priority

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

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 42%)
CISA exploited list	No
Weakness	CWE-120
Published	2023-04-17
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: apng optimizer project

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

Am I affected?

Timeline

2023-04-17 15:15 UTCPublished CVE record published
2026-06-17 05:45 UTCUpdated Record last modified

apng optimizer project apng optimizer DOWNGRADE

Affected: 1.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4

1. Check installed version

apt-cache policy apng-optimizer || rpm -q apng-optimizer || apng-optimizer --version

2. No fixed release: DOWNGRADE to a release before 1.4 (Debian / Ubuntu)

apt-cache madison apng-optimizer sudo apt install apng-optimizer=<VERSION_BEFORE_1.4> sudo apt-mark hold apng-optimizer

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

dnf --showduplicates list apng-optimizer sudo dnf downgrade apng-optimizer-<VERSION_BEFORE_1.4> sudo dnf versionlock add apng-optimizer

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-2023-27705?

apng optimizer: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-27705 being exploited?

CVE-2023-27705 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-2023-27705 affect?

CVE-2023-27705 affects apng optimizer. Severity is high (CVSS 7.5). APNG_Optimizer v1.4 was discovered to contain a buffer overflow via the component /apngopt/ubuntu.png.

How urgent is CVE-2023-27705?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Ubuntu vulnerabilities

References

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