Lexbor up to 2.6.x ISO‑2022‑JP Encoder integer underflow

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in Lexbor up to 2.6.x. This vulnerability affects unknown code of the component ISO‑2022‑JP Encoder. Such manipulation leads to integer underflow. This vulnerability is uniquely identified as CVE-2026-29078. The attack can be launched remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Lexbor up to 2.6.x. Affected by this issue is an unknown functionality of the component ISO‑2022‑JP Encoder. The manipulation with an unknown input leads to a integer underflow vulnerability. Using CWE to declare the problem leads to CWE-191. The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. Impacted is availability. CVE summarizes:

Lexbor is a web browser engine library. Prior to 2.7.0, the ISO‑2022‑JP encoder in Lexbor fails to reset the temporary size variable between iterations. The statement ctx->buffer_used -= size with a stale size = 3 causes an integer underflow that wraps to SIZE_MAX. Afterwards, memcpy is called with a negative length, leading to an out‑of‑bounds read from the stack and an out‑of‑bounds write to the heap. The source data is partially controllable via the contents of the DOM tree. This vulnerability is fixed in 2.7.0.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-29078 since 03/03/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available.

The vulnerability scanner Nessus provides a plugin with the ID 302265 (Linux Distros Unpatched Vulnerability : CVE-2026-29078), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.7.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (302265). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Integer underflow
CWE: CWE-191 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 302265
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-29078

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Lexbor 2.7.0

Timelineinfo

03/03/2026 CVE reserved
03/13/2026 +10 days Advisory disclosed
03/13/2026 +0 days VulDB entry created
03/20/2026 +7 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-29078 (🔒)
GCVE (CVE): GCVE-0-2026-29078
GCVE (VulDB): GCVE-100-351002

Entryinfo

Created: 03/13/2026 20:17
Updated: 03/20/2026 05:49
Changes: 03/13/2026 20:17 (65), 03/15/2026 06:34 (2), 03/20/2026 05:49 (12)
Complete: 🔍
Cache ID: 216:9A1:103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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