CVE-2026-41898: rust-openssl Unchecked Callback Length Vulnerability

HIGH
Advisory Identifier: GHSA-hppc-g8h3-xhp3
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CWE-126 CWE-130
Published
Advisory Summary

CVE-2026-41898 is a HIGH unchecked callback length vulnerability (CWE-126: Buffer Over-read) affecting rust-openssl libraries in the crates.io ecosystem. The issue involves unchecked callback length in psk/cookie trampolines leaks adjacent memory to peer. Remediation is available by upgrading affected packages to version 0.10.78.

CVE-2026-41898 at a Glance

CVE Identifier CVE-2026-41898
GHSA Identifier GHSA-hppc-g8h3-xhp3
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-126: Buffer Over-read
Affected Product rust-openssl
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix CVE-2026-41898

To remediate this vulnerability, upgrade all affected rust-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-2026-41898, inspect your project dependencies for rust-openssl:

inspect dependencies for openssl

Analyze the terminal output to locate any version of rust-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-126: Buffer Over-read, where the product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. In rust-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

The FFI trampolines behind `SslContextBuilder::set_psk_client_callback`, `set_psk_server_callback`, `set_cookie_generate_cb`, and `set_stateless_cookie_generate_cb` forwarded the user closure's returned usize directly to OpenSSL without checking it against the `&mut [u8]` that was handed to the closure. This can lead to buffer overflows and other unintended consequences.

CVE-2026-41898 Affected rust-openssl Versions

1 component(s)
Fixed Versions:
0.10.78
Product / Package Ecosystem Affected Versions Fixed Version
openssl
 crates.io
≥ 0.9.24
< 0.10.78
0.10.78

References

GitHub Advisory / Wiki ADVISORY
https://github.com/rust-openssl/rust-openssl/security/advisories/GHSA-hppc-g8h3-xhp3
NVD — CVE-2026-41898 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-41898
rust-openssl Source Repository REPOSITORY
https://github.com/rust-openssl/rust-openssl/pull/2607
Security Fix Commit FIX COMMIT
https://github.com/rust-openssl/rust-openssl/commit/1d109020d98fff2fb2e45c39a373af3dff99b24c
rust-openssl Source Repository REPOSITORY
https://github.com/rust-openssl/rust-openssl
rust-openssl Release RELEASE
https://github.com/rust-openssl/rust-openssl/releases/tag/openssl-v0.10.78

Frequently Asked Questions

What is CVE-2026-41898?
CVE-2026-41898 is a security vulnerability in rust-openssl involving Unchecked callback length in PSK/cookie trampolines leaks adjacent memory to peer under CWE-126: Buffer Over-read.
Which rust-openssl versions are affected?
Affected versions include releases prior to 0.10.78 across affected packages: openssl.
What version fixes CVE-2026-41898?
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-2026-41898?
CVE-2026-41898 is classified under CWE-126: Buffer Over-read (The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.).
How can I check crates.io dependencies for CVE-2026-41898?
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-hppc-g8h3-xhp3",
  "modified" : "2026-04-27T16:29:44Z",
  "published" : "2026-04-22T21:00:57Z",
  "aliases" : [ "CVE-2026-41898" ],
  "summary" : "rust-openssl: Unchecked callback length in PSK/cookie trampolines leaks adjacent memory to peer",
  "details" : "The FFI trampolines behind `SslContextBuilder::set_psk_client_callback`, `set_psk_server_callback`, `set_cookie_generate_cb`,  and `set_stateless_cookie_generate_cb` forwarded the user closure's returned usize directly to OpenSSL without checking it against the `&mut [u8]` that was handed to the closure. This can lead to buffer overflows and other unintended consequences.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "openssl"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.9.24"
      }, {
        "fixed" : "0.10.78"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/rust-openssl/rust-openssl/security/advisories/GHSA-hppc-g8h3-xhp3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-41898"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rust-openssl/rust-openssl/pull/2607"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rust-openssl/rust-openssl/commit/1d109020d98fff2fb2e45c39a373af3dff99b24c"
  }, {
    "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-126", "CWE-130" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-22T21:00:57Z",
    "nvd_published_at" : "2026-04-24T18:16:29Z"
  }
}