# CVE-2026-95105: Cloak AES-CTR cipher lacks ciphertext authentication, allowing chosen-plaintext forgery by bit flipping

> Attackers with write access to stored ciphertext can forge plaintext values via bit flipping due to missing integrity checks in the Cloak AES-CTR implementation.

- **Severity:** High 8.2 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** EEF-CVE-2026-95105, GHSA-hxq7-6hm2-6wvg

## What is CVE-2026-95105?

CVE-2026-95105 is a high-severity vulnerability in danielberkompas cloak, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-649 (Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking)

## Which versions are affected by CVE-2026-95105?

1 open source package ship an affected version, including cloak.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `cloak` | Hex | From 0.1.0-pre | None |

## How do I fix CVE-2026-95105?

No fix has been published for CVE-2026-95105 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-95105 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-95105 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-95105 and fix it if it is affected.

What it is: CVE-2026-95105 is a high-severity vulnerability in danielberkompas cloak, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-95105 exists.

Affected packages and fixed versions:
- cloak (Hex): affected from 0.1.0-pre; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-95105/ (Markdown: https://insights.sbomify.com/CVE-2026-95105/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-95105
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-95105
- OSV: https://osv.dev/vulnerability/CVE-2026-95105

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-95105/
Summaries are generated and may contain mistakes; the official description above is the record.