# CVE-2025-65637: Logrus is vulnerable to DoS when using Entry.Writer() > An attacker can cause a denial of service in applications using the logrus library by sending large single-line payloads that break the writer pipe. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Dec 2025 - **Updated:** 5 Dec 2025 - **Also known as:** AZL-71452, AZL-71473, AZL-71476, AZL-71479, AZL-71482, AZL-71500, AZL-71506, AZL-71510, AZL-71513, AZL-71516, AZL-71519, AZL-71534, AZL-71537, AZL-71543, AZL-71557, AZL-71560, AZL-71563, AZL-71566, AZL-71569, AZL-71572, AZL-71575, AZL-71602, AZL-71605, AZL-71614, AZL-71617, AZL-71620, AZL-71626, AZL-71629, AZL-71632, AZL-71638, BELL-CVE-2025-65637, CLEANSTART-2026-DU53299, CLEANSTART-2026-OJ67667, CLEANSTART-2026-TZ02456, CLEANSTART-2026-YM37209, CLEANSTART-2026-YY23230, DEBIAN-CVE-2025-65637, GHSA-4f99-4q7p-p3gh, GO-2025-4188, MINI-3q7x-p8pc-v6vc, MINI-8cv7-jqv7-cmmj, MINI-9gfm-wq55-9v29, MINI-cm5f-cx96-wr8r, MINI-fg7j-v7m6-4m79, MINI-g7hh-5p2g-2hvr, MINI-h72p-r7x8-qhp5, MINI-rwwv-f4x2-77f5, MINI-vrqv-3949-5xj5, MINI-wph8-99qf-m752, OESA-2026-1270, OESA-2026-1271, OESA-2026-1277, OESA-2026-1278, OESA-2026-2309, OESA-2026-2359, RHSA-2026:11804, RHSA-2026:12273, RHSA-2026:13971, RHSA-2026:15940, RHSA-2026:15941, RHSA-2026:2519, RHSA-2026:2520, RHSA-2026:2658, RHSA-2026:2670, RHSA-2026:2685, RHSA-2026:2686, RHSA-2026:2687, RHSA-2026:2688, RHSA-2026:2746, RHSA-2026:2973, RHSA-2026:4580, RHSA-2026:7238, UBUNTU-CVE-2025-65637 ## What is CVE-2025-65637? CVE-2025-65637 is a high-severity denial of service vulnerability in n/a, published on 4 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official 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. Weakness: CWE-400 (Uncontrolled Resource Consumption) ## Which versions are affected by CVE-2025-65637? 7 open source packages ship an affected version, including github.com/sirupsen/logrus. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/sirupsen/logrus` | Go | All versions | 1.8.3, 1.9.1, 1.9.3 | | `github.com/sirupsen/logrus` | Go | All versions | 1.8.3 | | `github.com/sirupsen/logrus` | Go | All versions | 1.8.3 | | `github.com/sirupsen/logrus` | Go | From 1.9.0 | 1.9.1 | | `github.com/sirupsen/logrus` | Go | From 1.9.0 | 1.9.1 | | `github.com/sirupsen/logrus` | Go | From 1.9.2 | 1.9.3 | | `github.com/sirupsen/logrus` | Go | From 1.9.2 | 1.9.3 | | `openshift` | Red Hat:openshift:4.12::el8 | All versions | 0:4.12.0-202604271501.p2.gedc7ba9.assembly.stream.el8 | | `openshift-hyperkube` | Red Hat:openshift:4.12::el8 | All versions | 0:4.12.0-202604271501.p2.gedc7ba9.assembly.stream.el8 | | `openshift` | Red Hat:openshift:4.12::el9 | All versions | 0:4.12.0-202604271501.p2.gedc7ba9.assembly.stream.el9 | | `openshift-hyperkube` | Red Hat:openshift:4.12::el9 | All versions | 0:4.12.0-202604271501.p2.gedc7ba9.assembly.stream.el9 | | `openshift` | Red Hat:openshift:4.13::el8 | All versions | 0:4.13.0-202603240119.p2.g7aa9360.assembly.stream.el8 | | `openshift-hyperkube` | Red Hat:openshift:4.13::el8 | All versions | 0:4.13.0-202603240119.p2.g7aa9360.assembly.stream.el8 | | `openshift` | Red Hat:openshift:4.13::el9 | All versions | 0:4.13.0-202603240119.p2.g7aa9360.assembly.stream.el9 | | `openshift-hyperkube` | Red Hat:openshift:4.13::el9 | All versions | 0:4.13.0-202603240119.p2.g7aa9360.assembly.stream.el9 | | `openshift` | Red Hat:openshift:4.14::el8 | All versions | 0:4.14.0-202602170118.p2.ga3faddd.assembly.stream.el8 | | `openshift-hyperkube` | Red Hat:openshift:4.14::el8 | All versions | 0:4.14.0-202602170118.p2.ga3faddd.assembly.stream.el8 | | `openshift` | Red Hat:openshift:4.14::el9 | All versions | 0:4.14.0-202602170118.p2.ga3faddd.assembly.stream.el9 | | `openshift-hyperkube` | Red Hat:openshift:4.14::el9 | All versions | 0:4.14.0-202602170118.p2.ga3faddd.assembly.stream.el9 | | `openshift` | Red Hat:openshift:4.16::el8 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el8 | | `openshift-hyperkube` | Red Hat:openshift:4.16::el8 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el8 | | `openshift-kube-apiserver` | Red Hat:openshift:4.16::el8 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el8 | | `openshift-kube-controller-manager` | Red Hat:openshift:4.16::el8 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el8 | | `openshift-kube-scheduler` | Red Hat:openshift:4.16::el8 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el8 | | `openshift-kubelet` | Red Hat:openshift:4.16::el8 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el8 | | `microshift` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-greenboot` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-multus` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-multus-release-info` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-networking` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-olm` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-olm-release-info` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-release-info` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `microshift-selinux` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.58-202603160404.p0.gb9661ec.assembly.4.16.58.el9 | | `openshift` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el9 | | `openshift-hyperkube` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el9 | | `openshift-kube-apiserver` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el9 | | `openshift-kube-controller-manager` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el9 | | `openshift-kube-scheduler` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el9 | | `openshift-kubelet` | Red Hat:openshift:4.16::el9 | All versions | 0:4.16.0-202602100409.p2.g41c4e9b.assembly.stream.el9 | Products: Turbopuffer Logrus. ## How do I fix CVE-2025-65637? Upgrade github.com/sirupsen/logrus to a fixed version for your release line: 1.8.3, 1.9.1 or 1.9.3. ## Is CVE-2025-65637 being exploited? There is no known exploitation of CVE-2025-65637 in the wild and no public exploit code. Public exploit code: - CVE-2025-65637: Logrus Denial of Service Vulnerability (github_poc): https://github.com/mjuanxd/logrus-dos-poc ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-65637 and fix it if it is affected. What it is: CVE-2025-65637 is a high-severity denial of service vulnerability in n/a, published on 4 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-65637 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/sirupsen/logrus (Go): affected all versions; fixed in 1.8.3, 1.9.1, 1.9.3 - github.com/sirupsen/logrus (Go): affected all versions; fixed in 1.8.3 - github.com/sirupsen/logrus (Go): affected all versions; fixed in 1.8.3 - github.com/sirupsen/logrus (Go): affected from 1.9.0; fixed in 1.9.1 - github.com/sirupsen/logrus (Go): affected from 1.9.0; fixed in 1.9.1 - github.com/sirupsen/logrus (Go): affected from 1.9.2; fixed in 1.9.3 - github.com/sirupsen/logrus (Go): affected from 1.9.2; fixed in 1.9.3 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-65637/ (Markdown: https://insights.sbomify.com/CVE-2025-65637/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-65637 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-65637 - OSV: https://osv.dev/vulnerability/CVE-2025-65637 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-65637/ Summaries are generated and may contain mistakes; the official description above is the record.