CVE-2026-58216: Samba: kpasswd service: kpasswd packet that contains malformed asn.1 might cause the server to access 6 bytes of unallocated memory leading server to crash
Vulnerability summary
CVE-2026-58216 is a medium (CVSS 5.3) Out-of-bounds Read vulnerability in samba. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 40.2% of scored vulnerabilities.
Not severe (CVSS 5.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 13 · Related 14Timeline
- 30-07-2026PublishedVulnerability first disclosed.
- 31-07-2026Last modifiedVulnerability information updated.
Description
An out-of-bounds read flaw was found in Samba's Kerberos Key Distribution Center's (KDC) password change (kpasswd) service. When processing malformed ASN.1-encoded Kerberos password change request, Samba server miscalculates the structure size and attempts to read up to six bytes beyond the end of the allocated buffer. While this out-of-bounds read typically results in a harmless decryption failure, if the read hits unmapped memory, it causes the KDC process to crash. An authenticated attacker can send a specially crafted kpasswd request containing malformed ASN.1 data to trigger the out-of-bounds read, which may cause the KDC process to terminate, resulting in a denial of service.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.46%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.46% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- sambaAll versions (No fix recorded) | < 2:4.22.10+dfsg-0+deb13u2 | < 2:4.24.5+dfsg-1
Ubuntu1 product
- sambaAll versions (No fix recorded) | < 2:4.15.13+dfsg-0ubuntu1.13 | < 2:4.19.5+dfsg-4ubuntu9.7 | < 2:4.23.6+dfsg-1ubuntu2.2
2 vendors · 2 products
