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MEDIUM severity

CVE-2024-12797 cryptography

MEDIUMFix: openssl/openssl@738d4f9

CVE-2024-12797 is a medium-severity (CVSS 6.3) CWE-392 vulnerability in cryptography. A fix is available for cryptography — see the affected versions and patch details below.

RFC7250 handshakes with unauthenticated servers don't abort as expected

Also known asGHSA-79v4-65xg-pq4gPYSEC-2026-1284
Published
Feb 11, 2025
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-12797.

EPSS Exploitation Probability

via FIRST.org ↗
2.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs84th percentile — riskier than 84% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2024-12797 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐍cryptography

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Issue summary: Clients using RFC7250 Raw Public Keys (RPKs) to authenticate a server may fail to notice that the server was not authenticated, because handshakes don't abort as expected when the SSL_VERIFY_PEER verification mode is set.

Impact summary: TLS and DTLS connections using raw public keys may be vulnerable to man-in-middle attacks when server authentication failure is not detected by clients.

RPKs are disabled by default in both TLS clients and TLS servers. The issue only arises when TLS clients explicitly enable RPK use by the server, and the server, likewise, enables sending of an RPK instead of an X.509 certificate chain. The affected clients are those that then rely on the handshake to fail when the server's RPK fails to match one of the expected public keys, by setting the verification mode to SSL_VERIFY_PEER.

Clients that enable server-side raw public keys can still find out that raw public key verification failed by calling SSL_get_verify_result(), and those that do, and take appropriate action, are not affected. This issue was introduced in the initial implementation of RPK support in OpenSSL 3.2.

The FIPS modules in 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIcryptography42.0.0&&< 44.0.144.0.1pip install --upgrade 'cryptography==44.0.1'

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cryptography, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update cryptography to 44.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-12797 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-12797 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2024-12797. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This issue was introduced in the initial implementation of RPK support in OpenSSL 3.2, which was first shipped in RHEL 9.5. Earlier releases of OpenSSL provided in RHEL prior to 9.5 are not affected. RPKs are disabled by default in both TLS clients and TLS servers. The issue only arises when TLS clients explicitly…

ProductFixed inAdvisory
Discovery 1 for RHEL 9discovery/discovery-server-rhel9:1.12.1-2RHSA-2025:1487
Red Hat Enterprise Linux 10openssl-1:3.2.2-16.el10RHBA-2025:6314
Red Hat Enterprise Linux 9openssl-1:3.2.2-6.el9_5.1RHSA-2025:1330
RHOL-5.9-RHEL-9openshift-logging/cluster-logging-operator-bundle:v5.9.12-13RHSA-2025:1985
Service Interconnect 1.4 for RHEL 9service-interconnect/skupper-config-sync-rhel9:1.4.8-1RHSA-2025:9895
Service Interconnect 1 for RHEL 9service-interconnect/skupper-config-sync-rhel9:1.5.5-5RHSA-2025:1925
Service Interconnect 1 for RHEL 9service-interconnect/skupper-config-sync-rhel9:1.8.5-1RHSA-2025:4005
Builds for Red Hat OpenShift 1.3.2openshift-builds/openshift-builds-git-cloner-rhel9:1.3.1-1741784043RHSA-2025:2754
UbuntuMEDIUM

Frequently Asked Questions

Issue summary: Clients using RFC7250 Raw Public Keys (RPKs) to authenticate a server may fail to notice that the server was not authenticated, because handshakes don't abort as expected when the SSL_VERIFY_PEER verification mode is set. Impact summary: TLS and DTLS connections using raw public keys may be vulnerable to man-in-middle attacks when server authentication failure is not detected by clients. RPKs are disabled by default in both TLS clients and TLS servers. The issue only arises when TLS clients explicitly enable RPK use by the server, and the server, likewise, enables sending of
O3 Security · Impact-Aware SCA

Is CVE-2024-12797 in your dependencies?

O3 Security finds CVE-2024-12797 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2024-12797: cryptography (Medium 6.3) | O3 Security