CVE-2020-35898
Use after free in actix-utils
An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.
- Record
CVE-2020-35898- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - CVSS 2.0
- 6.4 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:P - Weakness
- CWE-416
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.
- Record
CVE-2020-35898- Updated
- 2026-11-02
EUVDEUVD-2021-1747 No score
An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.
- Record
EUVD-2021-1747- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-hhw2-pqhf-vmx2
Use after free in actix-utils
An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.
- Record
GHSA-hhw2-pqhf-vmx2- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
OSVGHSA-hhw2-pqhf-vmx2
Use after free in actix-utils
An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.
- Record
GHSA-hhw2-pqhf-vmx2- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
OSVRUSTSEC-2020-0045
bespoke Cell implementation allows obtaining several mutable references to the same data
The custom implementation of a Cell primitive in the affected versions of this crate does not keep track of mutable references to the underlying data.
This allows obtaining several mutable references to the same object which may result in arbitrary memory corruption, most likely use-after-free.
The flaw was corrected by switching from a bespoke Cell<T> implementation to Rc<RefCell<T>>.
- Record
RUSTSEC-2020-0045- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
actix-utilscrates.io |
before 2.0.0 | 2.0.0 |
actix-utilscrates.io |
0.0.0-0 up to 2.0.0 | 2.0.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-35898 is a critical vulnerability (CVSS 9.1) in Actix Actix-utils, published January 8, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.43%, the 73rd percentile. Fixed in actix-utils 2.0.0.