How severe is CVE-2023-50455?

CVE-2023-50455 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-2023-50455 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-50455?

CVE-2023-50455 primarily affects Zammad. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-50455?

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-2023-50455 published?

CVE-2023-50455 was published on 2023-12-10 and last updated on 2026-06-17.

CVE-2023-50455

CVE-2023-50455 is a high-severity vulnerability in Zammad 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)
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Zammad
Published: 2023-12-10
Last modified: 2026-06-17

Description

An issue was discovered in Zammad before 6.2.0. Due to lack of rate limiting in the "email address verification" feature, an attacker could send many requests for a known address to cause Denial Of Service (generation of many emails, which would also spam the victim).

Frequently asked questions

What is CVE-2023-50455?: An issue was discovered in Zammad before 6.2.0. Due to lack of rate limiting in the "email address verification" feature, an attacker could send many requests for a known address to cause Denial Of Service (generation of many emails, which would also spam the victim).
How severe is CVE-2023-50455?: CVE-2023-50455 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-2023-50455 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-50455?: CVE-2023-50455 primarily affects Zammad. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-50455?: 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-2023-50455 published?: CVE-2023-50455 was published on 2023-12-10 and last updated on 2026-06-17.

References

https://zammad.com/en/advisories/zaa-2023-06

Affected products (3)

cpe:2.3:a:zammad:zammad:6.1.0:-:*:*:*:*:*:*
cpe:2.3:a:zammad:zammad:6.1.0:alpha:*:*:*:*:*:*
cpe:2.3:a:zammad:zammad:6.2.0:alpha:*:*:*:*:*:*

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