VulnerabilityPublished 27 Mar 2024Updated 4 Nov 2025

CVE-2023-46049: LLVM · NULL Pointer Dereference

Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 12:54 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Mar 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 26 Oct 2026.

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 or the CVSS exploit maturity 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

AI-suggested

Avoid processing untrusted or unauthenticated pdflatex.fmt or .o files with llvm-lto until a patch is released.
Implement input validation and sanitization in build pipelines to detect and reject malformed or suspicious files before they reach llvm-lto.
Monitor LLVM project communications and security advisories closely for any forthcoming patches or updates addressing this vulnerability.
Use containerization or sandboxing techniques to isolate build environments, limiting the impact of potential crashes on broader systems.
Incorporate robust error handling and automated recovery mechanisms in continuous integration workflows to minimize disruption from llvm-lto crashes.
Consider temporarily downgrading to a prior LLVM version if feasible and if it does not contain this vulnerability.
Educate development teams about the vulnerability and encourage cautious handling of input files related to llvm-lto processes.

Description

LLVM 15.0.0 has a NULL pointer dereference in the parseOneMetadata() function via a crafted pdflatex.fmt file (or perhaps a crafted .o file) to llvm-lto. NOTE: this is disputed because the relationship between pdflatex.fmt and any LLVM language front end is not explained, and because a crash of the llvm-lto application should be categorized as a usability problem.

Impact

For European organizations, the primary impact of CVE-2023-46049 is operational disruption due to denial of service in build or compilation pipelines that utilize LLVM 15.0.0's llvm-lto tool. This could delay software development, testing, or deployment activities, especially in sectors heavily reliant on LLVM toolchains such as software development firms, embedded systems manufacturers, and research institutions. Confidentiality and integrity of data are not directly impacted, reducing the risk of data breaches or code tampering. However, repeated crashes could lead to productivity losses and increased troubleshooting overhead. Organizations using automated build systems or continuous integration pipelines that incorporate llvm-lto should be aware of this vulnerability to avoid unexpected failures. Since no exploits are known in the wild, the immediate risk is low, but targeted attacks or accidental crashes from malformed inputs remain possible. The lack of a patch means organizations must rely on procedural mitigations until a fix is available.

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 4 Nov 2025, 18:59 UTC

WeaknessesCWE-476

Technical details

References

Community reviews

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