4.8
MEDIUM CVSS 4.0
CVE-2025-8733
GNU Bison Local Assertion Vulnerability
Description

A flaw has been found in GNU Bison up to 3.8.2. This affects the function __obstack_vprintf_internal of the file obprintf.c. Executing manipulation can lead to reachable assertion. The attack requires local access. The exploit has been published and may be used. It is still unclear if this vulnerability genuinely exists. The issue could not be reproduced from a GNU Bison 3.8.2 tarball run in a Fedora 42 container.

INFO

Published Date :

Aug. 8, 2025, 6:15 p.m.

Last Modified :

Aug. 19, 2025, 5:15 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2025-8733 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Gnu bison
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 LOW [email protected]
CVSS 3.1 LOW [email protected]
CVSS 4.0 MEDIUM [email protected]
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-8733.

URL Resource
https://github.com/akimd/bison/issues/113
https://github.com/akimd/bison/issues/114
https://vuldb.com/?ctiid.319229
https://vuldb.com/?id.319229
https://vuldb.com/?submit.622298
https://vuldb.com/?submit.622299
https://www.gnu.org/
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-8733 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-8733 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-8733 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-8733 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Aug. 19, 2025

    Action Type Old Value New Value
    Added Tag disputed
    Changed Description A vulnerability was found in GNU Bison up to 3.8.2. It has been rated as problematic. This issue affects the function __obstack_vprintf_internal of the file obprintf.c. The manipulation leads to reachable assertion. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used. A flaw has been found in GNU Bison up to 3.8.2. This affects the function __obstack_vprintf_internal of the file obprintf.c. Executing manipulation can lead to reachable assertion. The attack requires local access. The exploit has been published and may be used. It is still unclear if this vulnerability genuinely exists. The issue could not be reproduced from a GNU Bison 3.8.2 tarball run in a Fedora 42 container.
  • New CVE Received by [email protected]

    Aug. 08, 2025

    Action Type Old Value New Value
    Added Description A vulnerability was found in GNU Bison up to 3.8.2. It has been rated as problematic. This issue affects the function __obstack_vprintf_internal of the file obprintf.c. The manipulation leads to reachable assertion. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
    Added CVSS V2 (AV:L/AC:L/Au:S/C:N/I:N/A:P)
    Added CWE CWE-617
    Added Reference https://github.com/akimd/bison/issues/113
    Added Reference https://github.com/akimd/bison/issues/114
    Added Reference https://vuldb.com/?ctiid.319229
    Added Reference https://vuldb.com/?id.319229
    Added Reference https://vuldb.com/?submit.622298
    Added Reference https://vuldb.com/?submit.622299
    Added Reference https://www.gnu.org/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 4.8
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 3.3
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 1.7
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact