How severe is CVE-2026-34720?

CVE-2026-34720 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-34720 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34720?

CVE-2026-34720 primarily affects Zammad. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-34720?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-34720 have an EU (EUVD) identifier?

Yes. CVE-2026-34720 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20560.

When was CVE-2026-34720 published?

CVE-2026-34720 was published on 2026-04-08 and last updated on 2026-06-17.

CVE-2026-34720

CVE-2026-34720 is a medium-severity vulnerability in Zammad with a CVSS 3.x base score of 4.3. 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-346.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v4: 2.3
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-20560
Weakness: CWE-346
Affected product: Zammad
Published: 2026-04-08
Last modified: 2026-06-17

Description

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the SSO mechanism in Zammad was not verifying the header originates from a trusted SSO proxy/gateway before applying further actions on it. This vulnerability is fixed in 7.0.1 and 6.5.4.

Frequently asked questions

What is CVE-2026-34720?: Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the SSO mechanism in Zammad was not verifying the header originates from a trusted SSO proxy/gateway before applying further actions on it. This vulnerability is fixed in 7.0.1 and 6.5.4.
How severe is CVE-2026-34720?: CVE-2026-34720 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-34720 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34720?: CVE-2026-34720 primarily affects Zammad. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-34720?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34720 have an EU (EUVD) identifier?: Yes. CVE-2026-34720 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20560.
When was CVE-2026-34720 published?: CVE-2026-34720 was published on 2026-04-08 and last updated on 2026-06-17.

References

https://github.com/zammad/zammad/security/advisories/GHSA-hcv6-w4h9-p2p7

Affected products (2)

cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:*
cpe:2.3:a:zammad:zammad:7.0.0:*:*:*:*:*:*:*

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