Quadratic CPU use in Text::CSV_XS getline on CR-only input
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · 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. Impact type from CWE-407.
Summary
Text::CSV_XS versions before 1.65 for Perl are affected. With default options, getline copies the whole unparsed remainder of the input for each record, so CSV with CR-only line endings (CWE-407) makes CPU use grow with the square of the input size. An unauthenticated remote attacker who can send such CSV to a reader can exhaust CPU time, and a megabyte of input takes seconds to process.
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 allow quadratic CPU use by copying the unparsed remainder per record of CR-only input in getline. With eol unset, the default, getline reads with Perl's default line separator, so input with CR-only line endings arrives as one chunk. After each record the parser copies the whole unparsed remainder into a new buffer, which the next call parses and copies again, so the work grows with the square of the input size. A reader with default options that is sent CSV with classic Mac line endings spends seconds of CPU time on a megabyte of input.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
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. Red Hat lists Red Hat Enterprise Linux 7, 9 and 10 as affected, with no fix and no plan available.
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-2026-110755
- 2026-10-18 Alias added: GHSA-chcw-qm6q-pg64
- 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
References
Sources
- CVE-2026-110755 · CVE Program
- CVE-2026-110755 · NVD
- FIRST EPSS
- GHSA-chcw-qm6q-pg64 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-110755 · Red Hat security data · CC BY 4.0
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