# CVE-2026-22796: ASN1_TYPE Type Confusion in the PKCS7_digest_from_attributes() function

> An attacker can cause a denial of service in applications verifying PKCS#7 signatures by providing malformed data that triggers a null pointer dereference.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Jan 2026
- **Updated:** 15 Oct 2026
- **Also known as:** ALPINE-CVE-2026-22796, AZL-75299, AZL-75348, AZL-75905, AZL-76110, AZL-76161, AZL-78579, BELL-CVE-2026-22796, CLEANSTART-2026-PQ44811, CLSA-2026-1770136337, DEBIAN-CVE-2026-22796, ECHO-f3f1-7685-1435, GHSA-r9hf-rxjm-gv2f, JLSEC-2026-270, MINI-5m6m-jch6-rhcc, MINI-g3rp-9rg4-vjcv, MINI-vq8c-vrvw-h2g8, UBUNTU-CVE-2026-22796

## What is CVE-2026-22796?

CVE-2026-22796 is a medium-severity vulnerability in Openssl Openssl, published on 27 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Issue summary: A type confusion vulnerability exists in the signature
verification of signed PKCS#7 data where an ASN1_TYPE union member is
accessed without first validating the type, causing an invalid or NULL
pointer dereference when processing malformed PKCS#7 data.

Impact summary: An application performing signature verification of PKCS#7
data or calling directly the PKCS7_digest_from_attributes() function can be
caused to dereference an invalid or NULL pointer when reading, resulting in
a Denial of Service.

The function PKCS7_digest_from_attributes() accesses the message digest attribute
value without validating its type. When the type is not V_ASN1_OCTET_STRING,
this results in accessing invalid memory through the ASN1_TYPE union, causing
a crash.

Exploiting this vulnerability requires an attacker to provide a malformed
signed PKCS#7 to an application that verifies it. The impact of the
exploit is just a Denial of Service, the PKCS7 API is legacy and applications
should be using the CMS API instead. For these reasons the issue was
assessed as Low severity.

The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,
as the PKCS#7 parsing implementation is outside the OpenSSL FIPS module
boundary.

OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions)

## Which versions are affected by CVE-2026-22796?

It affects 1 product.


Products: Openssl Openssl.

## How do I fix CVE-2026-22796?

Apply the vendor's patch.

## Is CVE-2026-22796 being exploited?

There is no known exploitation of CVE-2026-22796 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-2026-22796 and fix it if it is affected.

What it is: CVE-2026-22796 is a medium-severity vulnerability in Openssl Openssl, published on 27 Jan 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-2026-22796 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-2026-22796/ (Markdown: https://insights.sbomify.com/CVE-2026-22796/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22796
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22796
- OSV: https://osv.dev/vulnerability/CVE-2026-22796

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22796/
Summaries are generated and may contain mistakes; the official description above is the record.