Text::CSV_XS for Perl returns a 0xFF byte not in the input
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
Text-CSV_XS versions before 1.65 for Perl are affected. When input ends with a separator and a lone CR, the parser reads the end of input as the next character and stores an end-of-file marker as a 0xFF byte in the last field (CWE-1286). A remote attacker who can supply CSV input without privileges or user interaction can make the application receive a byte that is not in its input.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
Text::CSV_XS versions before 1.65 for Perl return a 0xFF byte that is not in the input for an empty last field followed by a lone CR in parse. When the input to parse ends in a separator and a lone CR, the parser treats the end of the input as the next character and stores the end-of-file marker in the field as the byte 0xFF. With binary set, parse("a,\r") returns the fields "a" and "\xFF". On UTF-8 flagged input the last field is a UTF-8 flagged string holding that lone byte, which is malformed UTF-8. The same input with a non-empty last field is rejected as an error. A CRLF file read line by line and chomped ends this way when its last column is empty, so the application receives a byte that is not in its input.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Text-CSV_XS | before 1.65 | 1.65 | Patch available | CNA |
- Text-CSV_XS Vendor— Affected before 1.65 Fixed in 1.65 Patch available CNA
Remediation
Upgrade Text-CSV_XS to version 1.65, which fixes this flaw. Red Hat lists no available fix for Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7 and Red Hat Enterprise Linux 9.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Text-CSV_XS Fixed in 1.65
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-18 Threatist record created from CVE-2026-110759
- 2026-10-18 Alias added: GHSA-v3f5-7p3g-9fm4
- 2026-10-18 Affected versions changed · Red Hat
- 2026-10-18 CVSS score added · Red Hat
- 2026-10-20 CVSS score added · CISA ADP
- 2026-10-20 CISA SSVC decision points changed
- 2026-10-20 Priority changed: LOW → MEDIUM
References
Sources
- CVE-2026-110759 · CVE Program
- CVE-2026-110759 · NVD
- FIRST EPSS
- GHSA-v3f5-7p3g-9fm4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-110759 · Red Hat security data · CC BY 4.0
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