MongoDBGHSA-8g5h-p67q-9m5j
Persistent client crash loop via undersized FLE2 insert-update ciphertext in decryption path
High7.1CVE-2026-84971 · Published Sep 3, 2026
### Impact Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running. ### Patches Fixed in 1.20.4 ### Workarounds None. ### References https://jira.mongodb.org/browse/MONGOCRYPT-971
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| libmongocrypt Product | >= 1.7.0, < 1.20.4 | 1.20.4 |
Details and references
- CVSS 4.0
- CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- Severity from
- GitHub (reviewed advisory)
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