# CVE-2025-23016: Integer overflow in fcgi > An integer overflow in the FastCGI library allows attackers to trigger a heap-based buffer overflow via crafted IPC socket data, potentially leading to code execution or denial of service. - **Severity:** Critical 9.3 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 10 Jan 2025 - **Updated:** 26 Feb 2026 - **Also known as:** AZL-55397, AZL-55443, BELL-CVE-2025-23016, DEBIAN-CVE-2025-23016, DLA-4329-1, GHSA-9825-56cx-cfg6, MGASA-2025-0144, OESA-2025-1475, OESA-2025-2779, SUSE-SU-2025:02369-1, SUSE-SU-2025:02372-1, UBUNTU-CVE-2025-23016, USN-7486-1, openSUSE-SU-2025:15348-1 ## What is CVE-2025-23016? CVE-2025-23016 is a critical vulnerability in FastCGI fcgi, published on 10 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description FastCGI fcgi2 (aka fcgi) 2.x through 2.4.4 has an integer overflow (and resultant heap-based buffer overflow) via crafted nameLen or valueLen values in data to the IPC socket. This occurs in ReadParams in fcgiapp.c. Weakness: CWE-190 (Integer Overflow or Wraparound) ## Which versions are affected by CVE-2025-23016? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `FastCGI` | SUSE:Enterprise Storage 7.1 | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Module for Development Tools 15 SP6 | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Module for Development Tools 15 SP7 | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server 12 SP5-LTSS | All versions | 2.4.0-169.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server 15 SP3-LTSS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server 15 SP4-LTSS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server 15 SP5-LTSS | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 2.4.0-169.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server for SAP Applications 15 SP3 | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server for SAP Applications 15 SP4 | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | SUSE:Linux Enterprise Server for SAP Applications 15 SP5 | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | openSUSE:Leap 15.6 | All versions | 2.4.0-150000.4.3.1 | | `FastCGI` | openSUSE:Tumbleweed | All versions | 2.4.6-1.1 | ## How do I fix CVE-2025-23016? Apply the vendor's patch. ## Is CVE-2025-23016 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-23016 exists. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-23016 and fix it if it is affected. What it is: CVE-2025-23016 is a critical vulnerability in FastCGI fcgi, published on 10 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-23016 exists. Affected product: FastCGI fcgi. No package-level version data is available, so check the vendor advisory linked from the reference page. 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-2025-23016/ (Markdown: https://insights.sbomify.com/CVE-2025-23016/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-23016 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-23016 - OSV: https://osv.dev/vulnerability/CVE-2025-23016 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-23016/ Summaries are generated and may contain mistakes; the official description above is the record.