QOS.CH Sarl logback logback-core (HardenedObjectInputStream · Deserialization of Untrusted Data Vulnerability
Affects logbackSource GCVE Database
Public exploit available · CVSS 2.9 Low.
Data as of 12 Nov 2026, 19:41 UTC
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:P/RE:M/U:GreenExploitation evidence
Disclosed: evidence found.
CVE published 1 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10logbackpkg:deb/ubuntu/logback?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlogbackpkg:deb/ubuntu/logback?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10logbackpkg:deb/ubuntu/logback?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlogbackpkg:deb/ubuntu/logback?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSlogbackpkg:deb/ubuntu/logback?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSlogbackpkg:deb/ubuntu/logback?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, restrict access to SimpleSocketServer and SimpleSSLSocketServer interfaces to trusted sources to reduce risk of exploitation.
Description
A deserialization of untrusted data vulnerability exists in QOS.CH Sarl logback logback-core through version 1.5.33. The flaw allows an attacker who can influence serialized data sent to SimpleSocketServer or SimpleSSLSocketServer to instantiate Proxy objects, bypassing intended security restrictions. However, the deserialization is heavily restricted by HardenedObjectInputStream, and no practical remote code execution or significant privilege escalation has been identified.