CVE-2026-9828Logback deserialization whitelist bypass for java.lang and java.util
- 2.9LowCVSS base score
- 0.37%Exploitation in 30 daysEPSS · top 69% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Deserialization of untrusted data vulnerability in QOS.CH Sarl logback logback-core (HardenedObjectInputStream (logback-core) modules) allows Object Injection albeit heavily restricted. More precisely, an attacker able to influence serialized data sent to SimpleSocketServer or SimpleSSLSocketServer can instantiate objects from classes in the java.lang and java.util packages that are not explicitly blocked. Although deserialization is heavily restricted by HardenedObjectInputStream and no practical way to achieve remote code execution or significant privilege escalation has been identified, this issue constitutes a bypass of the intended security restrictions. This issue affects logback: through 1.5.32 inclusive.
Timeline
ID reserved
By NCSC.ch
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NCSC.chCNA (assigner) | 4.0 | Low2.9 | 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:L/U:Green |
| NVDNVD · Deferred | 4.0 | Low2.9 | 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:L/U:Green |
- EPSS (exploitation in 30 days)
- 0.37% · top 69% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.9.
Affected products
- affected ≤ 1.5.32
- unaffected 1.5.33
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavench.qos.logback:logback-coreGHSA-p47f-322f-whfh (opens in a new tab)
What to do
Solution: Upgrade to logback version 1.5.33.
Exploitation: Given that HardenedObjectInputStream used by SimpleSocketServer and SimpleSSLSockerServer already heavily restricts the set of deserializable classes, it is unlikely that the attacker can escalate the vulnerability to gain control of the target host.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-32895 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-p47f-322f-whfh (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-9828)Record last updated .