CVE-2026-128991

xschem 2.9.9 through 3.4.7 Out-of-Bounds Read via read_xschem_file() Embedded-Symbol Record

Published Nov 13, 2026 CVSS 4.0 · 5.8 Medium EPSS n/a KEV · Not listed

Description

xschem 2.9.9 through 3.4.7 contains an out-of-bounds read vulnerability in read_xschem_file() in src/save.c that mishandles embedded-symbol records lacking a preceding instance. Attackers can supply a crafted schematic beginning with a "[" record, causing xschem to read and dereference memory below the instance array and crash.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Stefan Schippers

xschem

unaffected

Version	Status	Constraints
`2.9.9`	affected	≤ 3.4.7

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

Attack Vector Local

Attack Complexity High

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://github.com/StefanSchippers/xschem
https://github.com/StefanSchippers/xschem/blob/3.4.7/src/save.c#L3138-L3141
https://github.com/StefanSchippers/xschem/commit/e29af39c6133c36bdaf66603fd663231e75517f1
https://www.vulncheck.com/advisories/xschem-2.9.9-through-3.4.7-out-of-bounds-read-via-read-xschem-file-embedded-symbol-record

History

Nov 13, 2026 3:15 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		xschem 2.9.9 through 3.4.7 contains an out-of-bounds read vulnerability in read_xschem_file() in src/save.c that mishandles embedded-symbol records lacking a preceding instance. Attackers can supply a crafted schematic beginning with a "[" record, causing xschem to read and dereference memory below the instance array and crash.
Title		xschem 2.9.9 through 3.4.7 Out-of-Bounds Read via read_xschem_file() Embedded-Symbol Record
Weaknesses		CWE-125
References		https://github.com/StefanSchippers/xschem https://github.com/StefanSchippers/xschem/blob/3.4.7/src/save.c#L3138-L3141 https://github.com/StefanSchippers/xschem/commit/e29af39c6133c36bdaf66603fd663231e75517f1 https://www.vulncheck.com/advisories/xschem-2.9.9-through-3.4.7-out-of-bounds-read-via-read-xschem-file-embedded-symbol-record
Metrics		cvssV3_1 `{'score': 5.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H'}` cvssV4_0 `{'score': 5.8, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N'}`