CVE-2024-9979VulnerabilityPublished 15 Oct 2024Updated 20 Nov 2025

CVE-2024-9979: pyo3 · Use After Free

Affects pyo3Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Oct 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
crates.iopyo3/pyo3`pkg:cargo/pyo3/pyo3`Other threats	Affected =0.22.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

In the interim, developers should audit their use of weak Python references in PyO3 to avoid unsound borrowing patterns that lead to use-after-free conditions. Employing memory safety tools such as sanitizers (e.g., AddressSanitizer) during development and testing can help detect similar issues early. Restricting local access to systems running vulnerable PyO3 versions can reduce exploitation risk. Additionally, applying strict access controls and isolating development environments can limit the impact of potential exploitation. Monitoring for unusual crashes or memory corruption in applications using PyO3 is recommended. Finally, maintain awareness of updates from PyO3 maintainers and security advisories for timely patch application.

Description

A flaw was found in PyO3. This vulnerability causes a use-after-free issue, potentially leading to memory corruption or crashes via unsound borrowing from weak Python references.

Impact

The impact of CVE-2024-9979 is primarily on applications using PyO3 0.22.0 for Python-Rust interoperability. Exploitation can lead to memory corruption, causing application crashes or potentially arbitrary code execution, which threatens confidentiality, integrity, and availability of affected systems. Although exploitation requires local access with low privileges and no user interaction, this still poses a risk in multi-user environments, development machines, or containerized environments where untrusted users have some level of access. The vulnerability could be leveraged to escalate privileges or disrupt services, especially in environments where PyO3 is part of critical infrastructure or development pipelines. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits over time. Organizations relying on PyO3 0.22.0 should consider the risk to their software supply chain and internal tooling.

References

Community reviews

Loading reviews…