# CVE-2023-23916: Denial of service in https://github.com/curl/curl

> A malicious server can cause curl to exhaust memory via excessive HTTP compression headers, leading to denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 23 Feb 2023
- **Updated:** 14 Oct 2026
- **Also known as:** ALPINE-CVE-2023-23916, ALSA-2023:1140, ALSA-2023:1701, AZL-13651, AZL-13653, AZL-13657, AZL-13658, AZL-34602, AZL-37839, CLEANSTART-2026-OS35106, CLSA-2023-1679349850, CLSA-2023-1679350332, CURL-CVE-2023-23916, DEBIAN-CVE-2023-23916, DLA-3341-1, DSA-5365-1, GHSA-v8vq-prc2-j6gx, JLSEC-2026-404, MGASA-2023-0054, OESA-2023-1122, OESA-2023-1123, RHSA-2023:1140, RHSA-2023:1701, RHSA-2023:1842, RLSA-2023:1140, SUSE-SU-2023:0425-1, UBUNTU-CVE-2023-23916

## What is CVE-2023-23916?

CVE-2023-23916 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 23 Feb 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An allocation of resources without limits or throttling vulnerability exists in curl <v7.88.0 based on the "chained" HTTP compression algorithms, meaning that a server response can be compressed multiple times and potentially with differentalgorithms. The number of acceptable "links" in this "decompression chain" wascapped, but the cap was implemented on a per-header basis allowing a maliciousserver to insert a virtually unlimited number of compression steps simply byusing many headers. The use of such a decompression chain could result in a "malloc bomb", making curl end up spending enormous amounts of allocated heap memory, or trying to and returning out of memory errors.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2023-23916?

It affects 9 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `curl` | AlmaLinux:8 | All versions | 7.61.1-25.el8_7.3 |
| `libcurl` | AlmaLinux:8 | All versions | 7.61.1-25.el8_7.3 |
| `libcurl-devel` | AlmaLinux:8 | All versions | 7.61.1-25.el8_7.3 |
| `libcurl-minimal` | AlmaLinux:8 | All versions | 7.61.1-25.el8_7.3 |
| `curl` | AlmaLinux:9 | All versions | 7.76.1-19.el9_1.2 |
| `curl-minimal` | AlmaLinux:9 | All versions | 7.76.1-19.el9_1.2 |
| `libcurl` | AlmaLinux:9 | All versions | 7.76.1-19.el9_1.2 |
| `libcurl-devel` | AlmaLinux:9 | All versions | 7.76.1-19.el9_1.2 |
| `libcurl-minimal` | AlmaLinux:9 | All versions | 7.76.1-19.el9_1.2 |
| `curl` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `curl-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `curl-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `curl-minimal-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `libcurl` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `libcurl-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `libcurl-devel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `libcurl-minimal` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `libcurl-minimal-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:7.61.1-25.el8_7.3 |
| `curl-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:7.76.1-19.el9_1.2 |
| `curl-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:7.76.1-19.el9_1.2 |
| `curl-minimal-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:7.76.1-19.el9_1.2 |
| `libcurl-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:7.76.1-19.el9_1.2 |
| `libcurl-devel` | Red Hat:enterprise_linux:9::appstream | All versions | 0:7.76.1-19.el9_1.2 |
| `libcurl-minimal-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:7.76.1-19.el9_1.2 |
| `curl` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `curl-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `curl-debugsource` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `curl-minimal` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `curl-minimal-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `libcurl` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `libcurl-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `libcurl-minimal` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `libcurl-minimal-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:7.76.1-19.el9_1.2 |
| `curl` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:7.61.1-22.el8_6.6 |
| `curl-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:7.61.1-22.el8_6.6 |
| `curl-debugsource` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:7.61.1-22.el8_6.6 |
| `curl-minimal-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:7.61.1-22.el8_6.6 |
| `libcurl` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:7.61.1-22.el8_6.6 |
| `libcurl-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:7.61.1-22.el8_6.6 |
| `libcurl-devel` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:7.61.1-22.el8_6.6 |

Products: Debian Debian Linux, Fedoraproject Fedora, Haxx Curl, Netapp Clustered Data Ontap, Netapp H300s Firmware, Netapp H410s Firmware, Netapp H500s Firmware, Netapp H700s Firmware, Splunk Universal Forwarder.

## How do I fix CVE-2023-23916?

Upgrade to a fixed version.

## Is CVE-2023-23916 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-23916 exists.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-23916 and fix it if it is affected.

What it is: CVE-2023-23916 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 23 Feb 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-23916 exists.

Affected product: Debian Debian Linux. 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-2023-23916/ (Markdown: https://insights.sbomify.com/CVE-2023-23916/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-23916
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-23916
- OSV: https://osv.dev/vulnerability/CVE-2023-23916

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-23916/
Summaries are generated and may contain mistakes; the official description above is the record.