High severityNVD Advisory· Published Mar 17, 2026· Updated Mar 18, 2026
pyOpenSSL DTLS cookie callback buffer overflow
CVE-2026-27459
Description
pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, if a user provided callback to set_cookie_generate_callback returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0.0, cookie values that are too long are now rejected.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
pyopensslPyPI | >= 22.0.0, < 26.0.0 | 26.0.0 |
Affected products
55- osv-coords54 versionspkg:apk/chainguard/airflow-2pkg:apk/chainguard/airflow-3pkg:apk/chainguard/authentikpkg:apk/chainguard/authentik-fipspkg:apk/chainguard/awxpkg:apk/chainguard/azpkg:apk/chainguard/datadog-agent-7.77-core-integrationspkg:apk/chainguard/datadog-agent-fips-7.71-core-integrationspkg:apk/chainguard/datadog-agent-fips-7.77-core-integrationspkg:apk/chainguard/datahub-ingestionpkg:apk/chainguard/ggshieldpkg:apk/chainguard/gitlab-toolbox-ce-18.7pkg:apk/chainguard/gitlab-toolbox-ce-18.8pkg:apk/chainguard/gitlab-toolbox-ce-18.9pkg:apk/chainguard/gitlab-toolbox-ce-fips-18.7pkg:apk/chainguard/gitlab-toolbox-ce-fips-18.8pkg:apk/chainguard/gitlab-toolbox-ce-fips-18.9pkg:apk/chainguard/gitlab-toolbox-ce-fips-19.0pkg:apk/chainguard/keep-apipkg:apk/chainguard/keep-api-fipspkg:apk/chainguard/localstackpkg:apk/chainguard/mitmproxypkg:apk/chainguard/py3-cassandra-medusapkg:apk/chainguard/request-1276pkg:apk/chainguard/superset-5.0pkg:apk/chainguard/superset-6.0pkg:apk/wolfi/airflow-3pkg:apk/wolfi/azpkg:apk/wolfi/datadog-agent-7.77-core-integrationspkg:apk/wolfi/ggshieldpkg:apk/wolfi/mitmproxypkg:apk/wolfi/py3-cassandra-medusapkg:apk/wolfi/superset-5.0pkg:apk/wolfi/superset-6.0pkg:pypi/pyopensslpkg:rpm/opensuse/python-pyOpenSSL&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/python-pyOpenSSL&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/python-pyOpenSSL&distro=openSUSE%20Tumbleweedpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-ESPOSpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-LTSSpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP5-ESPOSpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP5-LTSSpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Module%20for%20Public%20Cloud%2015%20SP4pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Module%20for%20Python%203%2015%20SP7pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP4-LTSSpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP5-LTSSpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP6-LTSSpkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%2016.0pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP4pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP5pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP6pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20applications%2016.0pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Micro%206.0pkg:rpm/suse/python-pyOpenSSL&distro=SUSE%20Linux%20Micro%206.1
< 2.11.2-r2+ 53 more
- (no CPE)range: < 2.11.2-r2
- (no CPE)range: < 3.1.8-r8
- (no CPE)range: < 2026.2.1-r4
- (no CPE)range: < 2026.2.1-r3
- (no CPE)range: < 24.6.1-r31
- (no CPE)range: < 2.84.0-r3
- (no CPE)range: < 7.77.3-r5
- (no CPE)range: < 7.71.2-r20
- (no CPE)range: < 7.77.3-r5
- (no CPE)range: < 1.5.0.1-r0
- (no CPE)range: < 1.51.0-r1
- (no CPE)range: < 18.7.5-r1
- (no CPE)range: < 18.8.5-r2
- (no CPE)range: < 18.9.2-r1
- (no CPE)range: < 18.7.5-r1
- (no CPE)range: < 18.8.5-r1
- (no CPE)range: < 18.9.2-r1
- (no CPE)range: < 19.0.2-r1
- (no CPE)range: < 0.51.0-r0
- (no CPE)range: < 0.51.0-r0
- (no CPE)range: < 4.14.0-r4
- (no CPE)range: < 12.2.3-r0
- (no CPE)range: < 0.27.0-r5
- (no CPE)range: < 0.27.0-r6
- (no CPE)range: < 5.0.0-r20
- (no CPE)range: < 6.0.0-r4
- (no CPE)range: < 3.1.8-r8
- (no CPE)range: < 2.84.0-r3
- (no CPE)range: < 7.77.3-r5
- (no CPE)range: < 1.51.0-r1
- (no CPE)range: < 12.2.3-r0
- (no CPE)range: < 0.27.0-r5
- (no CPE)range: < 5.0.0-r20
- (no CPE)range: < 6.0.0-r4
- (no CPE)range: >= 22.0.0, < 26.0.0
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 25.0.0-160000.3.1
- (no CPE)range: < 26.0.0-1.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 25.0.0-160000.3.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 23.2.0-150400.3.13.1
- (no CPE)range: < 25.0.0-160000.3.1
- (no CPE)range: < 24.0.0-2.1
- (no CPE)range: < 24.0.0-slfo.1.1_2.1
- pyca/pyopensslv5Range: >= 22.0.0, < 26.0.0
Patches
Vulnerability mechanics
References
5- github.com/advisories/GHSA-5pwr-322w-8jr4ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-27459ghsaADVISORY
- github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/CHANGELOG.rstghsax_refsource_MISCWEB
- github.com/pyca/pyopenssl/commit/57f09bb4bb051d3bc2a1abd36e9525313d5cd408ghsax_refsource_MISCWEB
- github.com/pyca/pyopenssl/security/advisories/GHSA-5pwr-322w-8jr4ghsax_refsource_CONFIRMWEB
News mentions
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