Array index error in the hb_ot_layout_build_glyph_classes function in pango/opentype/hb-ot-layout.cc in Pango before 1.27.1 allows context-dependent attackers to cause a denial of service (application crash) via a crafted font file, related to building a synthetic Glyph Definition (aka GDEF) table by using this font's charmap and the Unicode property database.
Conclusion & alert: CVE-2010-0421 is rated Moderate Risk (46.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.45%). 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 | 1.66% | 2.45% | +0.79% |
| 2 | 2025-03-30 | 3.09% | 1.66% | -1.43% |
| 3 | 2025-03-29 | — | 3.09% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2010-0421 not yet assigned priority: Debian including 1 source packages (pango1.0), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2010-0421 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2010-0421 |
ubuntu
|
low | CVE-2010-0421 low priority: Ubuntu including 1 source packages (pango1.0), 8 status rows across 8 suites (dapper, hardy, intrepid, jaunty, karmic, lucid, maverick, upstream): ignored 3, released 3, not-affected 2. | https://ubuntu.com/security/CVE-2010-0421 |