CVE-2019-3861: debian debian_linux Out-of-bounds Read
Vulnerability summary
CVE-2019-3861 is a critical (CVSS 9.1) Out-of-bounds Read vulnerability in debian debian_linux. EPSS estimates a 5.12% chance of exploitation in the next 30 days, higher than 92.3% of scored vulnerabilities.
Not severe (CVSS 5, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 13 · Related 9Timeline
- 25-03-2019PublishedVulnerability first disclosed.
- 14-10-2026Last modifiedVulnerability information updated.
Description
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH packets with a padding length value greater than the packet length are parsed. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
CVSS metrics
6 scores · 5 sources · 2 versions- CVE.orgCNA5.0MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:LDiffers
- OSV · AlpineEcosystem advisory · calculated9.1CriticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated9.1CriticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- OSV · DebianEcosystem advisory · calculated9.1CriticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS trend
Probability
5.12%
Chance of exploitation in the next 30 days
Percentile
92%
Versus all other CVEs
30-day change
No change 0.00 pp
From 5.12% 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, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- libssh2< 1.8.0-2.1
- debian_linuxEOL8.0
Alpine1 product
- libssh2≥ 0.15, < 1.8.1-r0
Libssh21 product
- libssh2≥ 0.15, ≤ 1.8.0
Netapp1 product
Opensuse1 product
- leapEOL15.0 | 42.3
The libssh2 project1 product
- libssh21.8.1
Ubuntu1 product
- libssh2< 1.4.3-2ubuntu0.2+esm2 | < 1.5.0-2ubuntu0.1+esm1 | All versions (No fix recorded)
7 vendors · 8 products
References
19 links- bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3861X Refsource CONFIRMIssue TrackingPatchThird Party Advisory
lists.debian.org/debian-lts-announce/2019/03/msg00032.htmlMailing ListX Refsource MLISTThird Party Advisory- lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.htmlVendor AdvisoryX Refsource SUSEThird Party Advisory