CVE-2025-65637

Name: CVE-2025-65637
Creator: NVD / NIST
Published: 2025-12-04T19:16:05.223+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.56%

Last modified Jun 17, 2026

CVE-2025-65637 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A denial-of-service vulnerability exists in github.com/sirupsen/logrus when using Entry.Writer() to log a single-line payload larger than 64KB without newline characters. Due to limitations in the internal bufio.Scanner, the read fails with "token too long" and the writer pipe is closed, leaving Writer() unusable and causing application unavailability (DoS). EPSS estimates a 0.56% chance of exploitation in the next 30 days.

Description

A denial-of-service vulnerability exists in github.com/sirupsen/logrus when using Entry.Writer() to log a single-line payload larger than 64KB without newline characters. Due to limitations in the internal bufio.Scanner, the read fails with "token too long" and the writer pipe is closed, leaving Writer() unusable and causing application unavailability (DoS). This affects versions < 1.8.3, 1.9.0, and 1.9.2. The issue is fixed in 1.8.3, 1.9.1, and 1.9.3+, where the input is chunked and the writer continues to function even if an error is logged.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.56%

42.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Turbopuffer	Logrus	< 1.8.3
Turbopuffer	Logrus	1.9.0
Turbopuffer	Logrus	1.9.2

References

https://github.com/mjuanxd/logrus-dos-pocExploit, Third Party Advisory
https://github.com/mjuanxd/logrus-dos-poc/blob/main/README.mdExploit, Third Party Advisory
https://github.com/sirupsen/logrus/issues/1370Exploit, Issue Tracking, Patch
https://github.com/sirupsen/logrus/pull/1376Issue Tracking, Patch
https://github.com/sirupsen/logrus/releases/tag/v1.8.3Release Notes
https://github.com/sirupsen/logrus/releases/tag/v1.9.1Release Notes
https://github.com/sirupsen/logrus/releases/tag/v1.9.3Release Notes
https://security.snyk.io/vuln/SNYK-GOLANG-GITHUBCOMSIRUPSENLOGRUS-5564391Exploit, Third Party Advisory

Timeline

Published: Dec 4, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-65637?

How severe is CVE-2025-65637?

CVE-2025-65637 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.56% probability of exploitation in the next 30 days.

How do I fix CVE-2025-65637?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-65637?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST