# CVE-2022-42916: curl: In curl before 7.86.0, the HSTS check could be bypassed to trick it into staying with HTTP

CVE-2022-42916 is fixed in 13 products on 1 platform, first by curl 7.81.0-1ubuntu1.6, released October 26, 2022. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2022-42916
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0251
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 26, 2022

## Description

In curl before 7.86.0, the HSTS check could be bypassed to trick it into staying with HTTP. Using its HSTS support, curl can be instructed to use HTTPS directly (instead of using an insecure cleartext HTTP step) even when HTTP is provided in the URL. This mechanism could be bypassed if the host name in the given URL uses IDN characters that get replaced with ASCII counterparts as part of the IDN conversion, e.g., using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop of U+002E (.). The earliest affected version is 7.77.0 2021-05-26.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | curl Debian 12.15 (bookworm) | 7.86.0-1 | [DEBIAN-CVE-2022-42916](https://patchblox.com/security/data/fix/linux/debian-cve-2022-42916.md) | Oct 29, 2022 |
| Linux | curl Debian 13.5 (trixie) | 7.86.0-1 | [DEBIAN-CVE-2022-42916](https://patchblox.com/security/data/fix/linux/debian-cve-2022-42916.md) | Oct 29, 2022 |
| Linux | curl Debian 14 | 7.86.0-1 | [DEBIAN-CVE-2022-42916](https://patchblox.com/security/data/fix/linux/debian-cve-2022-42916.md) | Oct 29, 2022 |
| Linux | curl Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.6 | [curl 7.81.0-1ubuntu1.6](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-curl-7.81.0-1ubuntu1.6.md) | Oct 26, 2022 |
| Linux | curl amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | curl-debuginfo amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | curl-debugsource amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | curl-minimal amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | curl-minimal-debuginfo amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | libcurl amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | libcurl-debuginfo amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | libcurl-devel amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | libcurl-minimal amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | libcurl-minimal-debuginfo amzn 2023 | 7.87.0-2.amzn2023.0.2 | [ALAS2023-2023-083](https://patchblox.com/security/data/fix/linux/alas2023-2023-083.md) | Feb 17, 2023 |
| Linux | libcurl3-gnutls Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.6 | [libcurl3-gnutls 7.81.0-1ubuntu1.6](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl3-gnutls-7.81.0-1ubuntu1.6.md) | Oct 26, 2022 |
| Linux | libcurl3-nss Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.6 | [libcurl3-nss 7.81.0-1ubuntu1.6](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl3-nss-7.81.0-1ubuntu1.6.md) | Oct 26, 2022 |
| Linux | libcurl4 Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.6 | [libcurl4 7.81.0-1ubuntu1.6](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl4-7.81.0-1ubuntu1.6.md) | Oct 26, 2022 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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