CVE-2026-2451

CVE-2026-2451 is a medium-severity vulnerability in Pretix Double Opt In Step with a CVSS 3.x base score of 6.5. 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-627.

Key facts

Description

Emails sent by pretix can utilize placeholders that will be filled with customer data. For example, when {name} is used in an email template, it will be replaced with the buyer's name for the final email. This mechanism contained a security-relevant bug: It was possible to exfiltrate information about the pretix system through specially crafted placeholder names such as {{event.__init__.__code__.co_filename}}. This way, an attacker with the ability to control email templates (usually every user of the pretix backend) could retrieve sensitive information from the system configuration, including even database passwords or API keys. pretix does include mechanisms to prevent the usage of such malicious placeholders, however due to a mistake in the code, they were not fully effective for this plugin. Out of caution, we recommend that you rotate all passwords and API keys contained in your pretix.cfg file.

Frequently asked questions

What is CVE-2026-2451?
Emails sent by pretix can utilize placeholders that will be filled with customer data. For example, when {name} is used in an email template, it will be replaced with the buyer's name for the final email. This mechanism contained a security-relevant bug: It was possible to exfiltrate information about the pretix system through specially crafted placeholder names such as {{event.__init__.__code__.co_filename}}. This way, an attacker with the ability to control email templates (usually every user of the pretix backend) could retrieve sensitive information from the system configuration, including even database passwords or API keys. pretix does include mechanisms to prevent the usage of such malicious placeholders, however due to a mistake in the code, they were not fully effective for this plugin. Out of caution, we recommend that you rotate all passwords and API keys contained in your pretix.cfg file.
How severe is CVE-2026-2451?
CVE-2026-2451 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-2451 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-2451?
CVE-2026-2451 primarily affects Pretix Double Opt In Step. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-2451?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-2451 have an EU (EUVD) identifier?
Yes. CVE-2026-2451 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-6096.
When was CVE-2026-2451 published?
CVE-2026-2451 was published on 2026-02-16 and last updated on 2026-06-17.

References

Affected products (2)

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