CVE-2025-27911: seq DoS — Fix

Description

An issue was discovered in Datalust Seq before 2024.3.13545. Expansion of identifiers in message templates can be used to bypass the system "Event body limit bytes" setting, leading to increased resource consumption. With sufficiently large events, there can be disk space exhaustion (if saved to disk) or a termination of the server process with an out-of-memory error.

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CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-770 CWE-770

Affected Products

Vendor	Product	Versions
datalust	seq	< 2024.3.13545

References

Advisories & Patches

https://github.com/datalust/seq-tickets/issues/2365

Other References

https://datalust.co/seq

Frequently Asked Questions

What is CVE-2025-27911? +

An issue was discovered in Datalust Seq before 2024.3.13545. Expansion of identifiers in message templates can be used to bypass the system "Event body limit bytes" setting, leading to increased resource consumption. With sufficiently large events, there can be disk space exhaustion (if saved to disk) or a termination of the server process with an out-of-memory error. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2025-27911? +

CVE-2025-27911 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-27911? +

CVE-2025-27911 affects products from datalust, specifically: seq. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-27911? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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