CVE-2021-26951
Out of bounds write in calamine
An issue was discovered in the calamine crate before 0.17.0 for Rust. It allows attackers to overwrite heap-memory locations because Vec::set_len is used without proper memory claiming, and this uninitialized memory is used for a user-provided Read operation, as demonstrated by Sectors::get.
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
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
9.8
An issue was discovered in the calamine crate before 0.17.0 for Rust. It allows attackers to overwrite heap-memory locations because Vec::set_len is used without proper memory claiming, and this uninitialized memory is used for a user-provided Read operation, as demonstrated by Sectors::get.
- Record
CVE-2021-26951- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-787, CWE-908
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the calamine crate before 0.17.0 for Rust. It allows attackers to overwrite heap-memory locations because Vec::set_len is used without proper memory claiming, and this uninitialized memory is used for a user-provided Read operation, as demonstrated by Sectors::get.
- Record
CVE-2021-26951- Updated
- 2026-11-02
EUVDEUVD-2021-1826 No score
An issue was discovered in the calamine crate before 0.17.0 for Rust. It allows attackers to overwrite heap-memory locations because Vec::set_len is used without proper memory claiming, and this uninitialized memory is used for a user-provided Read operation, as demonstrated by Sectors::get.
- Record
EUVD-2021-1826- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-ppqp-78xx-3r38
9.8
Out of bounds write in calamine
An issue was discovered in the calamine crate before 0.17.0 for Rust. It allows attackers to overwrite heap-memory locations because Vec::set_len is used without proper memory claiming, and this uninitialized memory is used for a user-provided Read operation, as demonstrated by Sectors::get.
- Record
GHSA-ppqp-78xx-3r38- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
9.8
An issue was discovered in the calamine crate before 0.17.0 for Rust. It allows attackers to overwrite heap-memory locations because Vec::set_len is used without proper memory claiming, and this uninitialized memory is used for a user-provided Read operation, as demonstrated by Sectors::get.
- Record
CVE-2021-26951- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-ppqp-78xx-3r38
9.8
Out of bounds write in calamine
An issue was discovered in the calamine crate before 0.17.0 for Rust. It allows attackers to overwrite heap-memory locations because Vec::set_len is used without proper memory claiming, and this uninitialized memory is used for a user-provided Read operation, as demonstrated by Sectors::get.
- Record
GHSA-ppqp-78xx-3r38- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSVRUSTSEC-2021-0015
9.8
`Sectors::get` accesses unclaimed/uninitialized memory
Affected versions of this crate arbitrarily calls Vec::set_len to increase length of a vector without claiming more memory for the vector. Affected versions of this crate
also calls user-provided Read on the uninitialized memory of the vector that was
extended with Vec::set_len.
This can overwrite active entities in adjacent heap memory and seems to be a major security issue. Also, calling user-provided Read on uninitialized memory is defined as UB in Rust.
- Record
RUSTSEC-2021-0015- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
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-2021-26951 is a critical vulnerability (CVSS 9.8) in Calamine Project Calamine, published January 6, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.75%, the 78th percentile. Fixed in calamine 0.17.0.