CVE-2025-55159: Slab Slab Allows Out-of-bounds Access Vulnerability

MODERATE
Advisory Identifier: GHSA-qx2v-8332-m4fv
Share
CWE-119
Published
Advisory Summary

CVE-2025-55159 is a MODERATE slab allows out-of-bounds access vulnerability (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer) affecting Slab libraries in the crates.io ecosystem. The issue involves slab allows out-of-bounds access in `get_disjoint_mut` due to incorrect bounds check. Remediation is available by upgrading affected packages to version 0.4.11.

CVE-2025-55159 at a Glance

CVE Identifier CVE-2025-55159
GHSA Identifier GHSA-qx2v-8332-m4fv
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
Affected Product Slab
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix CVE-2025-55159

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

slab fixed: 0.4.11 
Upgrade slab to 0.4.11
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 slab

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-55159, inspect your project dependencies for Slab:

inspect dependencies for slab

Analyze the terminal output to locate any version of Slab in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.4.11), 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-119: Improper Restriction of Operations within the Bounds of a Memory Buffer, where the product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. this may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. In Slab, 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

### Impact The `get_disjoint_mut` method in slab v0.4.10 incorrectly checked if indices were within the slab's capacity instead of its length, allowing access to uninitialized memory. This could lead to undefined behavior or potential crashes. ### Patches This has been fixed in slab v0.4.11. ### Workarounds Avoid using `get_disjoint_mut` with indices that might be beyond the slab's actual length, or upgrade to v0.4.11 or later. ### References - [https://github.com/tokio-rs/slab/pull/152](https://github.com/tokio-rs/slab/pull/152)

CVE-2025-55159 Affected Slab Versions

1 component(s)
Fixed Versions:
0.4.11
Product / Package Ecosystem Affected Versions Fixed Version
slab
 crates.io
≥ 0.4.10
< 0.4.11
All 1 versions
0.4.10
0.4.11

References

GitHub Advisory / Wiki ADVISORY
https://github.com/tokio-rs/slab/security/advisories/GHSA-qx2v-8332-m4fv
NVD — CVE-2025-55159 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-55159
Slab Source Repository REPOSITORY
https://github.com/tokio-rs/slab/pull/152
Security Fix Commit FIX COMMIT
https://github.com/tokio-rs/slab/commit/2d65c514bc964b192bab212ddf3c1fcea4ae96b8
Slab Source Repository REPOSITORY
https://github.com/tokio-rs/slab
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2025-0047.html

Frequently Asked Questions

What is CVE-2025-55159?
CVE-2025-55159 is a security vulnerability in Slab involving slab allows out-of-bounds access in `get_disjoint_mut` due to incorrect bounds check under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer.
Which Slab versions are affected?
Affected versions include releases prior to 0.4.11 across affected packages: slab.
What version fixes CVE-2025-55159?
Upgrading to 0.4.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is slab affected?
Yes, slab is affected in releases prior to 0.4.11. Upgrade your dependency to 0.4.11 or later.
What CWE is associated with CVE-2025-55159?
CVE-2025-55159 is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer (The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.).
How can I check crates.io dependencies for CVE-2025-55159?
Run the dependency tree command: 'inspect dependencies for slab'. 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-qx2v-8332-m4fv",
  "modified" : "2025-08-12T13:17:01Z",
  "published" : "2025-08-11T22:45:20Z",
  "aliases" : [ "CVE-2025-55159" ],
  "summary" : "slab allows out-of-bounds access in `get_disjoint_mut` due to incorrect bounds check",
  "details" : "### Impact\n\nThe `get_disjoint_mut` method in slab v0.4.10 incorrectly checked if indices were within the slab's capacity instead of its length, allowing access to uninitialized memory. This could lead to undefined behavior or potential crashes.\n\n### Patches\n\nThis has been fixed in slab v0.4.11.\n\n### Workarounds\n\nAvoid using `get_disjoint_mut` with indices that might be beyond the slab's actual length, or upgrade to v0.4.11 or later.\n\n### References\n\n- [https://github.com/tokio-rs/slab/pull/152](https://github.com/tokio-rs/slab/pull/152)",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "slab"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.4.10"
      }, {
        "fixed" : "0.4.11"
      } ]
    } ],
    "versions" : [ "0.4.10" ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/tokio-rs/slab/security/advisories/GHSA-qx2v-8332-m4fv"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-55159"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tokio-rs/slab/pull/152"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tokio-rs/slab/commit/2d65c514bc964b192bab212ddf3c1fcea4ae96b8"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/tokio-rs/slab"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2025-0047.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-119" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-11T22:45:20Z",
    "nvd_published_at" : "2025-08-11T23:15:28Z"
  }
}