An issue was discovered in the function mark_beginning_as_normal in nfa.c in flex 2.6.4.
Priority LOW 28CWE-674Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-674.
Summary
An issue was discovered in the function mark_beginning_as_normal in nfa.c in flex 2.6.4. There is a stack exhaustion problem caused by the mark_beginning_as_normal function making recursive calls to itself in certain scenarios involving lots of '*' characters. Remote attackers could leverage this vulnerability to cause a denial-of-service.
Why it matters now
EPSS 0.01601 75th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Deferred Red Hat: fix deferred
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-6293
- 2026-10-03 Alias added: GHSA-grpp-mcmx-p7pc
References
More Westes Flex vulnerabilities
- TI-2016-05442 Heap-based buffer overflow in the yy_get_next_buffer function in Flex before 2.6.1 might… CVSS 3.0CRITICAL 9.8
- TI-2006-00445 flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before… CVSS 2.0HIGH 7.5
Sources
- CVE-2019-6293 · CVE Program
- CVE-2019-6293 · NVD
- FIRST EPSS
- GHSA-grpp-mcmx-p7pc · GitHub Advisory Database · CC BY 4.0
- CVE-2019-6293 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences