Vulnerability · Published Oct 6, 2026 · Assigned by EEF
CVE-2026-95105Cloak AES-CTR cipher lacks ciphertext authentication, allowing chosen-plaintext forgery by bit flipping
High 8.2
In plain English
A high-severity security flaw in cloak from danielberkompas. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).
Official description
Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking vulnerability in danielberkompas cloak allows an attacker with write access to stored ciphertext to make it decrypt to a chosen value via bit flipping. Cloak.Ciphers.AES.CTR encrypts with AES-256 in CTR mode and stores the key tag, the IV and the ciphertext with no MAC. decrypt/2 checks only the key tag and the minimum length before it returns the plaintext, and Cloak.Ciphers.Deprecated.AES.CTR decrypts the legacy format the same way. CTR is a stream cipher, so a value XORed into the stored ciphertext is XORed into the plaintext at the same offset. An attacker who can write to the encrypted store (for example through SQL injection or a compromised replica) and who knows or can guess a stored plaintext can replace it with any value of the same length. The application receives that value with no error. This issue affects cloak: from 0.1.0-pre onward.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| danielberkompas | cloak | 0.1.0-pre – before * |
| danielberkompas | cloak | 2bd17019e285b55c5c218cc842537bf9280f24c3 – before * |
Weakness: CWE-649 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References
- EEF CNA record for CVE-2026-95105 related, third-party-advisory
- OSV record EEF-CVE-2026-95105 related
- Introducing commit 2bd1701 in danielberkompas/cloak related