CVE-2025-15467
Stack buffer overflow in CMS (Auth)EnvelopedData parsing
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Description
Issue summary: Parsing CMS AuthEnvelopedData or EnvelopedData message with maliciously crafted AEAD parameters can trigger a stack buffer overflow. Impact summary: A stack buffer overflow may lead to a crash, causing Denial of Service, or potentially remote code execution. When parsing CMS (Auth)EnvelopedData structures that use AEAD ciphers such as AES-GCM, the IV (Initialization Vector) encoded in the ASN.1 parameters is copied into a fixed-size stack buffer without verifying that its length fits the destination. An attacker can supply a crafted CMS message with an oversized IV, causing a stack-based out-of-bounds write before any authentication or tag verification occurs. Applications and services that parse untrusted CMS or PKCS#7 content using AEAD ciphers (e.g., S/MIME (Auth)EnvelopedData with AES-GCM) are vulnerable. Because the overflow occurs prior to authentication, no valid key material is required to trigger it. While exploitability to remote code execution depends on platform and toolchain mitigations, the stack-based write primitive represents a severe risk. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the CMS implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3 and 3.0 are vulnerable to this issue. OpenSSL 1.1.1 and 1.0.2 are not affected by this issue.
Official description from the CVE record, published by openssl. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.1 High 8.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: Required
A user has to do something first, such as opening a file or following a link.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: High
Serious or total effect on the secrecy of data.
Integrity impact: High
Serious or total effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | Required | A user has to do something first, such as opening a file or following a link. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | High | Serious or total effect on the secrecy of data. |
| Integrity impact | High | Serious or total effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
CVSS 3.1 Critical 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: High
Serious or total effect on the secrecy of data.
Integrity impact: High
Serious or total effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | High | Serious or total effect on the secrecy of data. |
| Integrity impact | High | Serious or total effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
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EPSS
- Score
- 0.74793 (74.8% probability)
- Percentile
- 99.5%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA assessment as of Mar 19, 2026
- Exploitation
- Public proof of concept recorded by CISA
- Automatable
- yes
- Technical impact
- total
Weakness (CWE)
Affected products
OpenSSL
- affected: 3.6.0 up to before 3.6.1
- affected: 3.5.0 up to before 3.5.5
- affected: 3.4.0 up to before 3.4.4
- affected: 3.3.0 up to before 3.3.6
- affected: 3.0.0 up to before 3.0.19
References
- OpenSSL Advisory (openssl-library.org)vendor-advisory
- 3.6.1 git commit (github.com)patch
- 3.5.5 git commit (github.com)patch
- 3.4.4 git commit (github.com)patch
- 3.3.6 git commit (github.com)patch
- 3.0.19 git commit (github.com)patch
- openwall.com/lists/oss-security/2026/01/27/10
- openwall.com/lists/oss-security/2026/02/25/6
Timeline
- ID reserved
- Record published
- Record last updated
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About CubePath
Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:50 UTC. Sources and licenses