CVE-2017-6961: An issue was discovered in apng2gif 1.7

Routine

MEDIUM 5.5DOWNGRADE

CVE-2017-6961 is a medium-severity flaw (CVSS 5.5) affecting apng2gif. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in apng2gif 1.7. There is improper sanitization of user input causing huge memory allocations, resulting in a crash. This is related to the read_chunk function using the pChunk->size value (within the PNG file) to determine the amount of memory to allocate.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-20
Published	2017-03-17
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: apng2gif project

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

Am I affected?

Timeline

2017-03-17 09:59 UTCPublished CVE record published
2026-06-17 01:23 UTCUpdated Record last modified

apng2gif project apng2gif DOWNGRADE

Affected: 1.7

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.7

1. Check installed version

apt-cache policy apng2gif || rpm -q apng2gif || apng2gif --version

2. No fixed release: DOWNGRADE to a release before 1.7 (Debian / Ubuntu)

apt-cache madison apng2gif sudo apt install apng2gif=<VERSION_BEFORE_1.7> sudo apt-mark hold apng2gif

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

dnf --showduplicates list apng2gif sudo dnf downgrade apng2gif-<VERSION_BEFORE_1.7> sudo dnf versionlock add apng2gif

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-2017-6961?

apng2gif: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-6961 being exploited?

CVE-2017-6961 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-2017-6961 affect?

CVE-2017-6961 affects apng2gif. Severity is medium (CVSS 5.5). An issue was discovered in apng2gif 1.7. There is improper sanitization of user input causing huge memory allocations, resulting in a crash. This is related to the read_chunk function using the pChunk->size value (within the PNG file) to de

How urgent is CVE-2017-6961?

Priority 33/100. No elevated risk signals yet.

Related CVEs

CVE-2017-6962 HIGH 7.5 DOWNGRADE An issue was discovered in apng2gif 1.7
CVE-2017-6960 HIGH 7.5 DOWNGRADE MITIGATE An issue was discovered in apng2gif 1.7

References

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