Vulnerability · Published Aug 11, 2025 · Assigned by GitHub_M

CVE-2025-55159slab allows out-of-bounds access in `get_disjoint_mut` due to incorrect bounds check

Medium 5.1

In plain English

A medium-severity memory corruption in slab from tokio-rs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).

Severity (CVSS 4.0)5.1Medium

Exploit odds (30 days)0.2%top 91.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

slab is a pre-allocated storage for a uniform data type. In version 0.4.10, the get_disjoint_mut method 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. This has been fixed in slab 0.4.11. A workaround for this issue involves to avoid using get_disjoint_mut with indices that might be beyond the slab's actual length.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Ubuntu:22.04:LTS	rust-slab	no fix listed	UBUNTU-CVE-2025-55159
Ubuntu:24.04:LTS	rust-slab	no fix listed	UBUNTU-CVE-2025-55159
Ubuntu:25.10	rust-slab	no fix listed	UBUNTU-CVE-2025-55159
Ubuntu:26.04:LTS	rust-slab	no fix listed	UBUNTU-CVE-2025-55159
Ubuntu:26.10	rust-slab	no fix listed	UBUNTU-CVE-2025-55159

Affected products (as reported)

Vendor	Product	Versions
tokio-rs	slab	>= 0.4.10, < 0.4.11

Weakness: CWE-119 · Vector: 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

References

https://github.com/tokio-rs/slab/security/advisories/GHSA-qx2v-8332-m4fv x_refsource_CONFIRM
https://github.com/tokio-rs/slab/pull/152 x_refsource_MISC
https://github.com/tokio-rs/slab/commit/2d65c514bc964b192bab212ddf3c1fcea4ae96b8 x_refsource_MISC