# CVE-2026-15310: zipfile: bzip2/LZMA/Zstandard members decompress without a max_length bound, defeating chunked-read memory limits > Attackers can cause memory exhaustion and denial of service by crafting zip files with specific compression algorithms that bypass memory limits in Python's zipfile module. - **Severity:** Low 2.1 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`) - **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:** 25 Aug 2026 - **Updated:** 2 Oct 2026 - **Also known as:** ALPINE-CVE-2026-15310, AZL-98208, AZL-98217, BELL-CVE-2026-15310, BIT-libpython-2026-15310, BIT-python-2026-15310, BIT-python-min-2026-15310, CLSA-2026-1791377791, DEBIAN-CVE-2026-15310, ECHO-961e-fb97-7609, GHSA-xj79-6hh5-9w6q, MINI-8mcg-f95p-q229, MINI-9q44-6wpv-mmq3, MINI-hf6c-3mx3-v98f, MINI-p4pv-4mqx-4gpp, MINI-vh5c-3f35-qmv3, OESA-2026-3755, OESA-2026-3756, OESA-2026-3757, OESA-2026-3920, PSF-2026-39, UBUNTU-CVE-2026-15310, openSUSE-SU-2026:11950-1 ## What is CVE-2026-15310? CVE-2026-15310 is a low-severity denial of service vulnerability in CPython, published on 25 Aug 2026. 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 When decompressing crafted zip files using the bzip/LZMA/Zstandard compressions, Python could use an attacker-controlled size to pre-allocate memory, possibly resulting in memory exhaustion. Weakness: CWE-400 (Uncontrolled Resource Consumption) ## Which versions are affected by CVE-2026-15310? 3 open source packages ship an affected version, including libpython, python and python-min. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `libpython` | Bitnami | All versions | 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8 | | `python` | Bitnami | All versions | 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8 | | `python-min` | Bitnami | All versions | 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8 | | `python313` | openSUSE:Tumbleweed | All versions | 3.13.15-2.1 | ## How do I fix CVE-2026-15310? Upgrade libpython to a fixed version for your release line: 3.10.22, 3.11.17, 3.12.15 or 3.13.16. ## Is CVE-2026-15310 being exploited? There is no known exploitation of CVE-2026-15310 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-15310 and fix it if it is affected. What it is: CVE-2026-15310 is a low-severity denial of service vulnerability in CPython, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2026-15310 in the wild and no public exploit code. Affected packages and fixed versions: - libpython (Bitnami): affected all versions; fixed in 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8 - python (Bitnami): affected all versions; fixed in 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8 - python-min (Bitnami): affected all versions; fixed in 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8 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-2026-15310/ (Markdown: https://insights.sbomify.com/CVE-2026-15310/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15310 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15310 - OSV: https://osv.dev/vulnerability/CVE-2026-15310 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-15310/ Summaries are generated and may contain mistakes; the official description above is the record.