CVE-2026-79591
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of...
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
- Record
CVE-2026-79591- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2026-75745
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
- Record
EUVD-2026-75745- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8cvq-g9xh-jmpf
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of...
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
- Record
GHSA-8cvq-g9xh-jmpf- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
NVD
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
- Record
CVE-2026-79591- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-79591
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
- Record
DEBIAN-CVE-2026-79591- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-79591
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
- Record
UBUNTU-CVE-2026-79591- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
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: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 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-79591 is a high vulnerability (CVSS 7.8) in r-cran-readxl, published September 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. Fixed in r-cran-readxl 1.6.0-1.
References
github.com/libxls/libxls/issues/161
nvd.nist.gov/vuln/detail/CVE-2026-79591
security-tracker.debian.org/tracker/CVE-2026-79591
ubuntu.com/security/CVE-2026-79591
cve.org/CVERecord?id=CVE-2026-79591