CVE-2018-1000656: The Pallets Project flask version Before 0.12.3 contains a CWE-20: Improper Input Validation vulnerability in

Q: How do I fix CVE-2018-1000656?

flask: upgrade to 0.12.3; active iq: mitigate or apply the listed mitigation; hyper converged infrastructure: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2018-1000656 being exploited?

CVE-2018-1000656 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2018-1000656 affect?

CVE-2018-1000656 affects flask, active iq, hyper converged infrastructure. Severity is high (CVSS 7.5). The Pallets Project flask version Before 0.12.3 contains a CWE-20: Improper Input Validation vulnerability in flask that can result in Large amount of memory usage possibly leading to denial of service. This attack appear to be exploitable

Q: How urgent is CVE-2018-1000656?

Priority 54/100. High severity; EPSS top 10%: very likely to be exploited; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADEMITIGATEMITIGATE

CVE-2018-1000656 is a high-severity flaw (CVSS 7.5) affecting flask, active iq, hyper converged infrastructure. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Pallets Project flask version Before 0.12.3 contains a CWE-20: Improper Input Validation vulnerability in flask that can result in Large amount of memory usage possibly leading to denial of service. This attack appear to be exploitable via Attacker provides JSON data in incorrect encoding. This vulnerability appears to have been fixed in 0.12.3. NOTE: this may overlap CVE-2019-1010083.

Why this priority

High severity
EPSS top 10%: very likely to be exploited
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	3.9% (top 10%)
CISA exploited list	No
Weakness	CWE-20
Published	2018-08-20
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: netapp · palletsprojects

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

Am I affected?

Timeline

2018-08-20 19:31 UTCPublished CVE record published
2026-06-17 01:33 UTCUpdated Record last modified

palletsprojects flask UPGRADE

Affected: < 0.12.3

Fixed in: 0.12.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 0.12.3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade flask

Note

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

netapp active iq MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy active-iq || rpm -q active-iq || active-iq --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

netapp hyper converged infrastructure MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy hyper-converged-infrastructure || rpm -q hyper-converged-infrastructure || hyper-converged-infrastructure --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

netapp ontap select deploy utility MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ontap-select-deploy-utility || rpm -q ontap-select-deploy-utility || ontap-select-deploy-utility --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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-2018-1000656?

flask: upgrade to 0.12.3; active iq: mitigate or apply the listed mitigation; hyper converged infrastructure: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-1000656 being exploited?

CVE-2018-1000656 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-2018-1000656 affect?

CVE-2018-1000656 affects flask, active iq, hyper converged infrastructure. Severity is high (CVSS 7.5). The Pallets Project flask version Before 0.12.3 contains a CWE-20: Improper Input Validation vulnerability in flask that can result in Large amount of memory usage possibly leading to denial of service. This attack appear to be exploitable

How urgent is CVE-2018-1000656?

Priority 54/100. High severity; EPSS top 10%: very likely to be exploited; Remotely exploitable, no login, no user action

Software pages

Flask vulnerabilities

Related CVEs

CVE-2026-27205 MEDIUM 4.3 UPGRADE Flask is a web server gateway interface (WSGI) web application framework
CVE-2023-30861 HIGH 7.5 UPGRADE Flask is a lightweight WSGI web application framework
CVE-2019-1010083 HIGH 7.5 UPGRADE The Pallets Project Flask before 1.0 is affected by: unexpected memory usage

References

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