# CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes

> Attackers can forge empty messages with arbitrary AAD in AES-SIV and AES-GCM-SIV modes, bypassing authentication in applications using these specific OpenSSL ciphers.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jun 2026
- **Updated:** 10 Jun 2026
- **Also known as:** ALPINE-CVE-2026-45446, AZL-89808, AZL-89937, BELL-CVE-2026-45446, DEBIAN-CVE-2026-45446, GHSA-7phf-qpm5-q6p3, JLSEC-2026-1144, MINI-2f87-h6pc-qjx5, MINI-hvrm-fg87-3wx4, UBUNTU-CVE-2026-45446

## What is CVE-2026-45446?

CVE-2026-45446 is a medium-severity vulnerability in Openssl Openssl, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV
(RFC 8452) mishandle the authentication of AAD (Additional Authenticated
Data) with an empty ciphertext allowing a forgery of such messages.

Impact summary: An attacker can forge empty messages with arbitrary AAD
to the victim's application using these ciphers.

AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant AEAD
modes: they accept a key, nonce, optional AAD (bytes that are authenticated
but not encrypted), and plaintext, and produces ciphertext plus a 16-byte
tag. On decrypt, `EVP_DecryptFinal_ex()` is documented to return success only
if the tag is verified succesfully.

In OpenSSL's provider implementation of these ciphers, the expected tag is
computed only when decryption function is invoked with non-empty data.
If the caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without
invocation of the ciphertext update, which can happen when the received
ciphertext length is zero, the tag is never recalculated and still holds its
all-zeros value.

When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty
ciphertext, and all-zeros tag passes authentication under any key they do not
know, single-shot. When AES-SIV is used, for mounting the attack it's
necessary for the application to reuse the decryption context without
resetting the key.

AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since
OpenSSL 3.2.

No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support
either AES-GCM-SIV or AES-SIV. To mount an attack, the applications must
implement their own protocol and use the EVP interface. Also they must skip the
ciphertext update when a message with an empty ciphertext arrives.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this
issue, as these algorithms are not FIPS approved and the affected code is
outside the OpenSSL FIPS module boundary.

Weakness: CWE-325 (Missing Cryptographic Step)

## Which versions are affected by CVE-2026-45446?

It affects 1 product.


Products: Openssl Openssl.

## How do I fix CVE-2026-45446?

Apply the vendor's patch.

## Is CVE-2026-45446 being exploited?

There is no known exploitation of CVE-2026-45446 in the wild and no public exploit code.

## Other vulnerabilities in Openssl Openssl

- [CVE-2009-3245](https://insights.sbomify.com/CVE-2009-3245/): Null dereference in n/a (critical 10.0)
- [CVE-2006-3738](https://insights.sbomify.com/CVE-2006-3738/): Memory corruption in n/a (critical 10.0)
- [CVE-2026-63073](https://insights.sbomify.com/CVE-2026-63073/): Untrusted Sender DN Used as Format String in CMP Response Validation (critical 9.8)
- [CVE-2016-6309](https://insights.sbomify.com/CVE-2016-6309/): Use after free in n/a (critical 9.8)
- [CVE-2016-0799](https://insights.sbomify.com/CVE-2016-0799/): Integer overflow in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45446 and fix it if it is affected.

What it is: CVE-2026-45446 is a medium-severity vulnerability in Openssl Openssl, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45446 in the wild and no public exploit code.

Affected product: Openssl Openssl. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-45446/ (Markdown: https://insights.sbomify.com/CVE-2026-45446/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45446
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45446
- OSV: https://osv.dev/vulnerability/CVE-2026-45446

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45446/
Summaries are generated and may contain mistakes; the official description above is the record.