CVE-2021-3968: fedoraproject fedora Heap-based Buffer Overflow
CVSS: 8.5v2.0HighModified
AliasesALPINE-CVE-2021-3968UBUNTU-CVE-2021-3968DEBIAN-CVE-2021-3968
Published 19-11-2021Last modified 08-10-2026
Vulnerability summary
CVE-2021-3968 is a high (CVSS 8.5) Heap-based Buffer Overflow vulnerability in fedoraproject fedora. EPSS estimates a 2.23% chance of exploitation in the next 30 days, higher than 82.4% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
8.5/10
010
High · v2.0 (NVD)EPSS score
2.23%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference
Advisory lineage
Upstream 0 · Downstream 3 · Related 2Timeline
- 19-11-2021PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
vim is vulnerable to Heap-based Buffer Overflow
CVSS metrics
8 scores · 5 sources · 3 versionsHigh 8.0Preferred score · OSV · Alpine (Ecosystem advisory) · calculated from vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:HSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated8.0HighCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.0HighCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- NVDNIST8.0HighCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
High 8.0Preferred score · CVE.org (CNA)
CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated8.0HighCVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- NVDNIST8.0HighCVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
High 8.5Preferred score · NVD (NIST)
AV:N/AC:M/Au:S/C:C/I:C/A:CSourcesSingle source
EPSS trend
Probability
2.23%
Chance of exploitation in the next 30 days
Percentile
82%
Versus all other CVEs
30-day change
0.00 pp
From 2.23% on 18-09-2026
18-09-202618-10-2026
EPSS score2.23%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (huntr.dev)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Alpine1 product
- vim≥ 8.2.3430, < 8.2.3650-r0
Debian1 product
- vim< 2:8.2.3995-1
Fedoraproject1 product
- fedoraEOL34 | 35
Ubuntu1 product
- vim< 2:8.2.3995-1ubuntu2.1
5 vendors · 6 products
References
11 links- huntr.dev/bounties/00d62924-a7b4-4a61-ba29-acab2eaa1528X Refsource CONFIRMExploitIssue TrackingPatchThird Party Advisory
- github.com/vim/vim/commit/a062006b9de0b2947ab5fb376c6e67ef92a8cd69X Refsource MISCPatchThird Party Advisory
