CVE-2026-41678: Openssl Rust-openssl Has Incorrect Bounds Assertion Vulnerability

HIGH
Advisory Identifier: GHSA-8c75-8mhr-p7r9
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CWE-787
Published
Advisory Summary

CVE-2026-41678 is a HIGH rust-openssl has incorrect bounds assertion vulnerability (CWE-787: Out-of-bounds Write) affecting Openssl libraries in the crates.io ecosystem. The issue involves rust-openssl has incorrect bounds assertion in aes key wrap. Remediation is available by upgrading affected packages to version 0.10.78.

CVE-2026-41678 at a Glance

CVE Identifier CVE-2026-41678
GHSA Identifier GHSA-8c75-8mhr-p7r9
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Openssl
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix CVE-2026-41678

To remediate this vulnerability, upgrade all affected Openssl dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

openssl fixed: 0.10.78 
Upgrade openssl to 0.10.78
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for openssl

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-41678, inspect your project dependencies for Openssl:

inspect dependencies for openssl

Analyze the terminal output to locate any version of Openssl in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.10.78), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-787: Out-of-bounds Write, where the product writes data past the end, or before the beginning, of the intended buffer. In Openssl, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary ``aes::unwrap_key()`` has an incorrect bounds assertion on the out buffer size, which can lead to out-of-bounds write. ### Details ``aes::unwrap_key()`` contains an incorrect assertion: it checks that `out.len() + 8 <= in_.len()`, but this condition is reversed. The intended invariant is `out.len() >= in_.len() - 8`, ensuring the output buffer is large enough. Because of the inverted check, the function only accepts buffers at or below the minimum required size and rejects larger ones. If a smaller buffer is provided the function will write past the end of `out` by `in_.len() - 8 - out.len()` bytes, causing an out-of-bounds write from a safe public function. ### Impact Vulnerable applications using AES keywrap and allowing attacker controlled buffer sizes could have an attacker trigger an out-of-bounds write.

CVE-2026-41678 Affected Openssl Versions

1 component(s)
Fixed Versions:
0.10.78
Product / Package Ecosystem Affected Versions Fixed Version
openssl
 crates.io
≥ 0.10.24
< 0.10.78
0.10.78

References

GitHub Advisory / Wiki ADVISORY
https://github.com/rust-openssl/rust-openssl/security/advisories/GHSA-8c75-8mhr-p7r9
NVD — CVE-2026-41678 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-41678
Openssl Source Repository REPOSITORY
https://github.com/rust-openssl/rust-openssl/pull/2604
Security Fix Commit FIX COMMIT
https://github.com/rust-openssl/rust-openssl/commit/718d07ff8ff7be417d5b7a6a0047f1607520b3b6
Openssl Source Repository REPOSITORY
https://github.com/rust-openssl/rust-openssl
Openssl Release RELEASE
https://github.com/rust-openssl/rust-openssl/releases/tag/openssl-v0.10.78

Frequently Asked Questions

What is CVE-2026-41678?
CVE-2026-41678 is a security vulnerability in Openssl involving rust-openssl has incorrect bounds assertion in aes key wrap under CWE-787: Out-of-bounds Write.
Which Openssl versions are affected?
Affected versions include releases prior to 0.10.78 across affected packages: openssl.
What version fixes CVE-2026-41678?
Upgrading to 0.10.78 (or the latest patched release for your respective branch) resolves the vulnerability.
Is openssl affected?
Yes, openssl is affected in releases prior to 0.10.78. Upgrade your dependency to 0.10.78 or later.
What CWE is associated with CVE-2026-41678?
CVE-2026-41678 is classified under CWE-787: Out-of-bounds Write (The product writes data past the end, or before the beginning, of the intended buffer.).
How can I check crates.io dependencies for CVE-2026-41678?
Run the dependency tree command: 'inspect dependencies for openssl'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8c75-8mhr-p7r9",
  "modified" : "2026-04-27T16:41:53Z",
  "published" : "2026-04-22T21:17:32Z",
  "aliases" : [ "CVE-2026-41678" ],
  "summary" : "rust-openssl has incorrect bounds assertion in aes key wrap",
  "details" : "### Summary\n``aes::unwrap_key()`` has an incorrect bounds assertion on the out buffer size, which can lead to out-of-bounds write.\n\n### Details\n``aes::unwrap_key()`` contains an incorrect assertion: it checks that `out.len() + 8 <= in_.len()`, but this condition is reversed. The intended invariant is `out.len() >= in_.len() - 8`, ensuring the output buffer is large enough.\n\nBecause of the inverted check, the function only accepts buffers at or below the minimum required size and rejects larger ones. If a smaller buffer is provided the function will write past the end of `out` by `in_.len() - 8 - out.len()` bytes, causing an out-of-bounds write from a safe public function.\n\n### Impact\nVulnerable applications using AES keywrap and allowing attacker controlled buffer sizes could have an attacker trigger an out-of-bounds write.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "openssl"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.10.24"
      }, {
        "fixed" : "0.10.78"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/rust-openssl/rust-openssl/security/advisories/GHSA-8c75-8mhr-p7r9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-41678"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rust-openssl/rust-openssl/pull/2604"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rust-openssl/rust-openssl/commit/718d07ff8ff7be417d5b7a6a0047f1607520b3b6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rust-openssl/rust-openssl"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rust-openssl/rust-openssl/releases/tag/openssl-v0.10.78"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-22T21:17:32Z",
    "nvd_published_at" : "2026-04-24T18:16:29Z"
  }
}