CVE-2026-26825
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS...
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
5.3
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
- Record
CVE-2026-26825- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-908
- Updated
- 2026-11-02
CVE List
5.3
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
- Record
CVE-2026-26825- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-908
- Updated
- 2026-11-02
EUVDEUVD-2026-34179
5.3
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
- Record
EUVD-2026-34179- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-48jr-3rh3-95w6
5.3
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS...
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
- Record
GHSA-48jr-3rh3-95w6- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-908
- Updated
- 2026-11-02
OSV
5.3
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
- Record
CVE-2026-26825- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-26825
5.3
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
- Record
DEBIAN-CVE-2026-26825- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-26825
5.3
A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
- Record
UBUNTU-CVE-2026-26825- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:12110-1 No score
libxls-devel-1.6.4-1.1 on GA media
These are all security issues fixed in the libxls-devel-1.6.4-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12110-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:22128-1 No score
Security update for libxls
This update for libxls fixes the following issues:
Changes in libxls:
Update to release 1.6.4:
- Fix use of uninitialized memory in OLE parsing [boo#1267687, CVE-2026-26825]
- Fix use of uninitialized memory in read_MSAT [boo#1267608, CVE-2026-26824]
- Fix use of uninitialized memory in xls_parseWorkBook
- Fix out-of-bounds reads in the formula dumper
- Handle allocation failures in OLE, workbook and string code
- Read SummaryInformation streams at their real size
- Keep full precision when converting numeric cells to strings
- Fix "creation of UTF-8 locale failed" in xls2csv
Update to release 1.6.3:
- Fix style record size check on big-endian systems
- Fix header include in C++ mode
- Fix buffer overflows when parsing style records
- Fix infinite loop with self-referencing sectors
- Record
openSUSE-SU-2026:22128-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
r-cran-readxlDebian:12 |
All versions, plus listed versions 1.4.2-11.4.3-11.4.4-11.4.5-11.5.0-11.5.0.1-11.6.0-1 |
None known |
r-cran-readxlDebian:13 |
All versions, plus listed versions 1.4.5-11.5.0-11.5.0.1-11.6.0-1 |
None known |
r-cran-readxlDebian:14 |
before 1.6.0-1, plus listed versions 1.4.5-11.5.0-11.5.0.1-1 |
1.6.0-1 |
r-cran-readxlUbuntu:16.04:LTS |
All versions, plus listed versions 0.1.0-1 |
None known |
r-cran-readxlUbuntu:18.04:LTS |
All versions, plus listed versions 1.0.0-1build11.0.0-2 |
None known |
r-cran-readxlUbuntu:20.04:LTS |
All versions, plus listed versions 1.3.1-21.3.1-2build1 |
None known |
r-cran-readxlUbuntu:22.04:LTS |
All versions, plus listed versions 1.3.1-2build2 |
None known |
r-cran-readxlUbuntu:24.04:LTS |
All versions, plus listed versions 1.4.3-1 |
None known |
r-cran-readxlUbuntu:25.10 |
All versions, plus listed versions 1.4.5-1 |
None known |
r-cran-readxlUbuntu:26.10 |
All versions, plus listed versions 1.4.5-11.5.0-1 |
None known |
r-cran-readxlUbuntu:26.04:LTS |
All versions, plus listed versions 1.4.5-1 |
None known |
libxlsopenSUSE:Tumbleweed From an advisory covering 2 CVEs |
before 1.6.4-1.1 | 1.6.4-1.1 |
libxlsopenSUSE:Leap 16.0 From an advisory covering 2 CVEs |
before 1.6.4-bp160.1.1 | 1.6.4-bp160.1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-26825 is a medium vulnerability (CVSS 5.3) in Libxls Project Libxls, published June 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 15th percentile. Fixed in r-cran-readxl 1.6.0-1.