UBUNTU-CVE-2026-29078

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Source
https://ubuntu.com/security/CVE-2026-29078
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29078.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-29078
Upstream
Published
2026-03-13T19:54:00Z
Modified
2026-05-20T16:24:54.591271091Z
Severity
  • 8.2 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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->bufferused -= size with a stale size = 3 causes an integer underflow that wraps to SIZEMAX. 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.

References

Affected packages

Ubuntu:26.04:LTS / lexbor

Package

Name
lexbor
Purl
pkg:deb/ubuntu/lexbor?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.6.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "liblexbor2",
            "binary_version": "2.6.0-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29078.json"