# CVE-2026-81720: openssl_encrypt before 1.4.9 Denial of Service via Unbounded Argon2

> Attackers with local write access can cause a denial of service by crafting identity files with excessive memory costs in the openssl_encrypt library.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Aug 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-783h-8q2f-f762, GHSA-92rj-569v-9vqg, PYSEC-2026-3965

## What is CVE-2026-81720?

CVE-2026-81720 is a medium-severity denial of service vulnerability in Jahlives Openssl Encrypt, published on 27 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

openssl_encrypt before 1.4.9 fails to validate the memory_cost parameter from identity file protection blocks, allowing attackers to trigger out-of-memory conditions during key derivation. Attackers with write access to local identity stores can craft malicious identity files with excessive memory_cost values that cause the host to crash when unlocking identities before authentication.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-81720?

1 open source package ship an affected version, including openssl-encrypt. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `openssl-encrypt` | PyPI | All versions | 1.4.9 |

Products: Jahlives Openssl Encrypt.

## How do I fix CVE-2026-81720?

Upgrade openssl-encrypt to 1.4.9 or later.

## Is CVE-2026-81720 being exploited?

There is no known exploitation of CVE-2026-81720 in the wild and no public exploit code.

## Other vulnerabilities in Jahlives Openssl Encrypt

- [CVE-2026-81680](https://insights.sbomify.com/CVE-2026-81680/): openssl_encrypt before 1.4.9 Authentication Bypass via Recovery Slot Removal (critical 9.3)
- [CVE-2026-81681](https://insights.sbomify.com/CVE-2026-81681/): openssl_encrypt before 1.4.9 False Encryption via Cleartext Storage (critical 9.3)
- [CVE-2026-81685](https://insights.sbomify.com/CVE-2026-81685/): openssl_encrypt before 1.4.9 Text Injection via Recovery Slot Metadata (critical 9.3)
- [CVE-2026-81694](https://insights.sbomify.com/CVE-2026-81694/): openssl-encrypt before 1.4.9 Output Injection via Unsanitized Filenames in verify-usb Command (critical 9.3)
- [CVE-2026-81695](https://insights.sbomify.com/CVE-2026-81695/): openssl_encrypt before 1.4.9 Terminal Injection via key_id (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81720 and fix it if it is affected.

What it is: CVE-2026-81720 is a medium-severity denial of service vulnerability in Jahlives Openssl Encrypt, published on 27 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-81720 in the wild and no public exploit code.

Affected packages and fixed versions:
- openssl-encrypt (PyPI): affected all versions; fixed in 1.4.9

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-2026-81720/ (Markdown: https://insights.sbomify.com/CVE-2026-81720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81720
- OSV: https://osv.dev/vulnerability/CVE-2026-81720

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81720/
Summaries are generated and may contain mistakes; the official description above is the record.