# CVE-2025-6069: HTMLParser quadratic complexity when processing malformed inputs
> Attackers can cause denial of service in applications using Python's HTMLParser by submitting crafted malformed inputs that trigger quadratic complexity.
- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Jun 2025
- **Updated:** 31 Jul 2026
- **Also known as:** AZL-64173, AZL-64178, BIT-libpython-2025-6069, BIT-python-2025-6069, BIT-python-min-2025-6069, DEBIAN-CVE-2025-6069, ECHO-dc49-c687-112f, GHSA-j5cc-6rx8-ff96, MINI-9vrx-rrcg-33qp, MINI-jfvw-w577-8x8g, MINI-v53v-rxx2-qr96, MINI-xpf7-pq22-j657, OESA-2025-1758, OESA-2025-2329, OESA-2025-2330, OESA-2025-2331, PSF-2025-10, SUSE-SU-2025:02232-1, SUSE-SU-2025:02358-1, SUSE-SU-2025:02460-1, SUSE-SU-2025:02523-1, SUSE-SU-2025:02597-1, UBUNTU-CVE-2025-6069, openSUSE-SU-2025:15365-1, openSUSE-SU-2025:15366-1, openSUSE-SU-2025:15367-1
## What is CVE-2025-6069?
CVE-2025-6069 is a medium-severity denial of service vulnerability in CPython, published on 17 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.
### Official description
The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service.
Weakness: CWE-1333 (Inefficient Regular Expression Complexity)
## Which versions are affected by CVE-2025-6069?
3 open source packages ship an affected version, including libpython, python and python-min.
| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libpython` | Bitnami | All versions | 3.9.24, 3.10.19, 3.11.14, 3.12.12, 3.13.6 |
| `python` | Bitnami | All versions | 3.9.24, 3.10.19, 3.11.14, 3.12.12, 3.13.6 |
| `python-min` | Bitnami | All versions | 3.9.24, 3.10.19, 3.11.14, 3.12.12, 3.13.6 |
| `python` | SUSE:Linux Enterprise Module for Package Hub 15 SP6 | All versions | 2.7.18-150000.80.1 |
| `python-base` | SUSE:Linux Enterprise Module for Package Hub 15 SP6 | All versions | 2.7.18-150000.80.1 |
| `python` | SUSE:Linux Enterprise Module for Package Hub 15 SP7 | All versions | 2.7.18-150000.80.1 |
| `python-base` | SUSE:Linux Enterprise Module for Package Hub 15 SP7 | All versions | 2.7.18-150000.80.1 |
| `python311` | SUSE:Linux Enterprise Module for Public Cloud 15 SP4 | All versions | 3.11.13-150400.9.63.1 |
| `python311-core` | SUSE:Linux Enterprise Module for Public Cloud 15 SP4 | All versions | 3.11.13-150400.9.63.1 |
| `python` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 2.7.18-33.50.1 |
| `python-base` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 2.7.18-33.50.1 |
| `python-doc` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 2.7.18-33.50.1 |
| `python` | openSUSE:Leap 15.6 | All versions | 2.7.18-150000.80.1 |
| `python-base` | openSUSE:Leap 15.6 | All versions | 2.7.18-150000.80.1 |
| `python-doc` | openSUSE:Leap 15.6 | All versions | 2.7.18-150000.80.1 |
| `python310` | openSUSE:Leap 15.6 | All versions | 3.10.18-150400.4.85.1 |
| `python310-core` | openSUSE:Leap 15.6 | All versions | 3.10.18-150400.4.85.1 |
| `python310-documentation` | openSUSE:Leap 15.6 | All versions | 3.10.18-150400.4.85.1 |
| `python39` | openSUSE:Leap 15.6 | All versions | 3.9.23-150300.4.78.1 |
| `python39-core` | openSUSE:Leap 15.6 | All versions | 3.9.23-150300.4.78.1 |
| `python39-documentation` | openSUSE:Leap 15.6 | All versions | 3.9.23-150300.4.78.1 |
| `python311` | openSUSE:Tumbleweed | All versions | 3.11.13-3.1 |
| `python312` | openSUSE:Tumbleweed | All versions | 3.12.11-3.1 |
| `python313` | openSUSE:Tumbleweed | All versions | 3.13.5-3.1 |
## How do I fix CVE-2025-6069?
Upgrade libpython to a fixed version for your release line: 3.9.24, 3.10.19, 3.11.14 or 3.12.12.
## Is CVE-2025-6069 being exploited?
There is no known exploitation of CVE-2025-6069 in the wild and no public exploit code.
## Fix prompt for AI coding agents
```text
Check this codebase for CVE-2025-6069 and fix it if it is affected.
What it is: CVE-2025-6069 is a medium-severity denial of service vulnerability in CPython, published on 17 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-6069 in the wild and no public exploit code.
Affected packages and fixed versions:
- libpython (Bitnami): affected all versions; fixed in 3.9.24, 3.10.19, 3.11.14, 3.12.12, 3.13.6
- python (Bitnami): affected all versions; fixed in 3.9.24, 3.10.19, 3.11.14, 3.12.12, 3.13.6
- python-min (Bitnami): affected all versions; fixed in 3.9.24, 3.10.19, 3.11.14, 3.12.12, 3.13.6
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-2025-6069/ (Markdown: https://insights.sbomify.com/CVE-2025-6069/index.md)
```
## Sources
- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-6069
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-6069
- OSV: https://osv.dev/vulnerability/CVE-2025-6069
---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-6069/
Summaries are generated and may contain mistakes; the official description above is the record.