An issue was discovered in libxls before and including 1.6.1 when reading Microsoft Excel files. A NULL pointer dereference vulnerability exists when parsing XLS cells in libxls/xls2csv.c:199. It could allow a remote attacker to cause a denial of service via crafted XLS file.
Conclusion & alert: CVE-2020-27819 is rated Moderate Risk (41/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.83%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.27% | 0.83% | +0.56% |
| 2 | 2025-11-21 | 0.20% | 0.27% | +0.07% |
| 3 | 2025-11-18 | — | 0.20% | — |
Full EPSS history (9 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2020-27819 unimportant priority: Debian including 1 source packages (r-cran-readxl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2020-27819 |
ubuntu
|
medium | CVE-2020-27819 medium priority: Ubuntu including 1 source packages (r-cran-readxl), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needs-triage 6, DNE 1, not-affected 1. | https://ubuntu.com/security/CVE-2020-27819 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| libxls_project | libxls | < 1.6.2 | cpe:2.3:a:libxls_project:libxls:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=1903296 | Issue Tracking Third Party Advisory |