How severe is CVE-2019-11923?

CVE-2019-11923 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2019-11923 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-11923?

CVE-2019-11923 affects Facebook Mcrouter. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-11923?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-11923 published?

CVE-2019-11923 was published on 2019-12-04 and last updated on 2026-06-17.

CVE-2019-11923

CVE-2019-11923 is a high-severity vulnerability in Facebook Mcrouter with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Facebook Mcrouter
Published: 2019-12-04
Last modified: 2026-06-17

Description

In Mcrouter prior to v0.41.0, the deprecated ASCII parser would allocate a buffer to a user-specified length with no maximum length enforced, allowing for resource exhaustion or denial of service.

Frequently asked questions

What is CVE-2019-11923?: In Mcrouter prior to v0.41.0, the deprecated ASCII parser would allocate a buffer to a user-specified length with no maximum length enforced, allowing for resource exhaustion or denial of service.
How severe is CVE-2019-11923?: CVE-2019-11923 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2019-11923 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-11923?: CVE-2019-11923 affects Facebook Mcrouter. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-11923?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-11923 published?: CVE-2019-11923 was published on 2019-12-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:facebook:mcrouter:*:*:*:*:*:*:*:*

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