--- title: "CVE-2018-3639: Observable Discrepancy | CubePath" description: "Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes…" language: en source: https://cubepath.com/security/cve/CVE-2018-3639 --- # CVE-2018-3639: Observable Discrepancy | CubePath ## Description Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka Speculative Store Bypass (SSB), Variant 4. Official description from the CVE record, published by intel. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2018-3639) ## Key data ### CVSS 3.1 Medium 5.5 Score published by CISA-ADP in the CVE record. CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N | Metric | Value | What it means | | ---------------------- | --------- | ----------------------------------------------------------------------------------------- | | Attack vector | Local | The attacker needs local access to the system, or to trick a user into running something. | | Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. | | Privileges required | Low | A basic user account is needed. | | User interaction | None | No action from any user is needed. | | Scope | Unchanged | The impact stays within the vulnerable component. | | Confidentiality impact | High | Serious or total effect on the secrecy of data. | | Integrity impact | None | No effect on the trustworthiness of data. | | Availability impact | None | No effect on availability. | CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) . ### EPSS Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days. Score 0.60421 (60.4% probability) Percentile 99.2% Scores of Nov 10, 2026 Model v2026.06.15 ### CISA assessment as of May 29, 2026 Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA. Automatable no Technical impact partial ### Weakness (CWE) CWE catalog version 5.0. CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license. - [CWE-203](https://cwe.mitre.org/data/definitions/203.html) Observable Discrepancy ## Affected products Products listed in the CVE record, as the CNA published them. - Intel Corporation Multiple - affected: Multiple ## References Links listed in the CVE record. They lead to other sites, which CubePath does not control. - [RHSA-2018:1689](https://access.redhat.com/errata/RHSA-2018:1689) (access.redhat.com) vendor-advisory - [RHSA-2018:2162](https://access.redhat.com/errata/RHSA-2018:2162) (access.redhat.com) vendor-advisory - [RHSA-2018:1641](https://access.redhat.com/errata/RHSA-2018:1641) (access.redhat.com) vendor-advisory - [USN-3680-1](https://usn.ubuntu.com/3680-1/) (usn.ubuntu.com) vendor-advisory - [RHSA-2018:1997](https://access.redhat.com/errata/RHSA-2018:1997) (access.redhat.com) vendor-advisory - [RHSA-2018:1665](https://access.redhat.com/errata/RHSA-2018:1665) (access.redhat.com) vendor-advisory - [RHSA-2018:3407](https://access.redhat.com/errata/RHSA-2018:3407) (access.redhat.com) vendor-advisory - [RHSA-2018:2164](https://access.redhat.com/errata/RHSA-2018:2164) (access.redhat.com) vendor-advisory - [RHSA-2018:2001](https://access.redhat.com/errata/RHSA-2018:2001) (access.redhat.com) vendor-advisory - [RHSA-2018:3423](https://access.redhat.com/errata/RHSA-2018:3423) (access.redhat.com) vendor-advisory - [RHSA-2018:2003](https://access.redhat.com/errata/RHSA-2018:2003) (access.redhat.com) vendor-advisory - [USN-3654-1](https://usn.ubuntu.com/3654-1/) (usn.ubuntu.com) vendor-advisory - [RHSA-2018:1645](https://access.redhat.com/errata/RHSA-2018:1645) (access.redhat.com) vendor-advisory - [RHSA-2018:1643](https://access.redhat.com/errata/RHSA-2018:1643) (access.redhat.com) vendor-advisory - [RHSA-2018:1652](https://access.redhat.com/errata/RHSA-2018:1652) (access.redhat.com) vendor-advisory - [RHSA-2018:3424](https://access.redhat.com/errata/RHSA-2018:3424) (access.redhat.com) vendor-advisory - [RHSA-2018:3402](https://access.redhat.com/errata/RHSA-2018:3402) (access.redhat.com) vendor-advisory - [TA18-141A](https://www.us-cert.gov/ncas/alerts/TA18-141A) (us-cert.gov) third-party-advisory - [RHSA-2018:1656](https://access.redhat.com/errata/RHSA-2018:1656) (access.redhat.com) vendor-advisory - [RHSA-2018:1664](https://access.redhat.com/errata/RHSA-2018:1664) (access.redhat.com) vendor-advisory - [RHSA-2018:2258](https://access.redhat.com/errata/RHSA-2018:2258) (access.redhat.com) vendor-advisory - [RHSA-2018:1688](https://access.redhat.com/errata/RHSA-2018:1688) (access.redhat.com) vendor-advisory - [RHSA-2018:1658](https://access.redhat.com/errata/RHSA-2018:1658) (access.redhat.com) vendor-advisory - [RHSA-2018:1657](https://access.redhat.com/errata/RHSA-2018:1657) (access.redhat.com) vendor-advisory - [RHSA-2018:2289](https://access.redhat.com/errata/RHSA-2018:2289) (access.redhat.com) vendor-advisory - [RHSA-2018:1666](https://access.redhat.com/errata/RHSA-2018:1666) (access.redhat.com) vendor-advisory - [1042004](http://www.securitytracker.com/id/1042004) (securitytracker.com) vdb-entry - [RHSA-2018:1675](https://access.redhat.com/errata/RHSA-2018:1675) (access.redhat.com) vendor-advisory - [RHSA-2018:1660](https://access.redhat.com/errata/RHSA-2018:1660) (access.redhat.com) vendor-advisory - [RHSA-2018:1965](https://access.redhat.com/errata/RHSA-2018:1965) (access.redhat.com) vendor-advisory - [RHSA-2018:1661](https://access.redhat.com/errata/RHSA-2018:1661) (access.redhat.com) vendor-advisory - [RHSA-2018:1633](https://access.redhat.com/errata/RHSA-2018:1633) (access.redhat.com) vendor-advisory - [RHSA-2018:1636](https://access.redhat.com/errata/RHSA-2018:1636) (access.redhat.com) vendor-advisory - [RHSA-2018:1854](https://access.redhat.com/errata/RHSA-2018:1854) (access.redhat.com) vendor-advisory - [RHSA-2018:2006](https://access.redhat.com/errata/RHSA-2018:2006) (access.redhat.com) vendor-advisory - [RHSA-2018:2250](https://access.redhat.com/errata/RHSA-2018:2250) (access.redhat.com) vendor-advisory - [1040949](http://www.securitytracker.com/id/1040949) (securitytracker.com) vdb-entry - [RHSA-2018:3401](https://access.redhat.com/errata/RHSA-2018:3401) (access.redhat.com) vendor-advisory - [RHSA-2018:1737](https://access.redhat.com/errata/RHSA-2018:1737) (access.redhat.com) vendor-advisory - [RHSA-2018:1826](https://access.redhat.com/errata/RHSA-2018:1826) (access.redhat.com) vendor-advisory - [USN-3651-1](https://usn.ubuntu.com/3651-1/) (usn.ubuntu.com) vendor-advisory - [DSA-4210](https://www.debian.org/security/2018/dsa-4210) (debian.org) vendor-advisory - [44695](https://www.exploit-db.com/exploits/44695/) (exploit-db.com) exploit - [RHSA-2018:1651](https://access.redhat.com/errata/RHSA-2018:1651) (access.redhat.com) vendor-advisory - [RHSA-2018:1638](https://access.redhat.com/errata/RHSA-2018:1638) (access.redhat.com) vendor-advisory - [RHSA-2018:1696](https://access.redhat.com/errata/RHSA-2018:1696) (access.redhat.com) vendor-advisory - [RHSA-2018:2246](https://access.redhat.com/errata/RHSA-2018:2246) (access.redhat.com) vendor-advisory - [RHSA-2018:1644](https://access.redhat.com/errata/RHSA-2018:1644) (access.redhat.com) vendor-advisory - [RHSA-2018:1646](https://access.redhat.com/errata/RHSA-2018:1646) (access.redhat.com) vendor-advisory - [\[debian-lts-announce\] 20180718 \[SECURITY\] \[DLA 1423-1\] linux-4.9 new package](https://lists.debian.org/debian-lts-announce/2018/07/msg00020.html) (lists.debian.org) mailing-list - [RHSA-2018:1639](https://access.redhat.com/errata/RHSA-2018:1639) (access.redhat.com) vendor-advisory - [RHSA-2018:1668](https://access.redhat.com/errata/RHSA-2018:1668) (access.redhat.com) vendor-advisory - [RHSA-2018:1637](https://access.redhat.com/errata/RHSA-2018:1637) (access.redhat.com) vendor-advisory - [RHSA-2018:2948](https://access.redhat.com/errata/RHSA-2018:2948) (access.redhat.com) vendor-advisory - [VU#180049](https://www.kb.cert.org/vuls/id/180049) (kb.cert.org) third-party-advisory - [RHSA-2018:1686](https://access.redhat.com/errata/RHSA-2018:1686) (access.redhat.com) vendor-advisory - [RHSA-2018:2172](https://access.redhat.com/errata/RHSA-2018:2172) (access.redhat.com) vendor-advisory - [RHSA-2018:1663](https://access.redhat.com/errata/RHSA-2018:1663) (access.redhat.com) vendor-advisory - [USN-3652-1](https://usn.ubuntu.com/3652-1/) (usn.ubuntu.com) vendor-advisory - [RHSA-2018:1629](https://access.redhat.com/errata/RHSA-2018:1629) (access.redhat.com) vendor-advisory - [RHSA-2018:1655](https://access.redhat.com/errata/RHSA-2018:1655) (access.redhat.com) vendor-advisory - [RHSA-2018:1640](https://access.redhat.com/errata/RHSA-2018:1640) (access.redhat.com) vendor-advisory - [RHSA-2018:1669](https://access.redhat.com/errata/RHSA-2018:1669) (access.redhat.com) vendor-advisory - [RHSA-2018:1676](https://access.redhat.com/errata/RHSA-2018:1676) (access.redhat.com) vendor-advisory - [20180522 CPU Side-Channel Information Disclosure Vulnerabilities: May 2018](https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180521-cpusidechannel) (tools.cisco.com) vendor-advisory - [RHSA-2018:3425](https://access.redhat.com/errata/RHSA-2018:3425) (access.redhat.com) vendor-advisory - [RHSA-2018:2363](https://access.redhat.com/errata/RHSA-2018:2363) (access.redhat.com) vendor-advisory - [RHSA-2018:1632](https://access.redhat.com/errata/RHSA-2018:1632) (access.redhat.com) vendor-advisory - [RHSA-2018:1650](https://access.redhat.com/errata/RHSA-2018:1650) (access.redhat.com) vendor-advisory - [RHSA-2018:2396](https://access.redhat.com/errata/RHSA-2018:2396) (access.redhat.com) vendor-advisory - [RHSA-2018:2364](https://access.redhat.com/errata/RHSA-2018:2364) (access.redhat.com) vendor-advisory - [USN-3653-2](https://usn.ubuntu.com/3653-2/) (usn.ubuntu.com) vendor-advisory - [RHSA-2018:2216](https://access.redhat.com/errata/RHSA-2018:2216) (access.redhat.com) vendor-advisory - [USN-3655-1](https://usn.ubuntu.com/3655-1/) (usn.ubuntu.com) vendor-advisory - [RHSA-2018:1649](https://access.redhat.com/errata/RHSA-2018:1649) (access.redhat.com) vendor-advisory - [RHSA-2018:2309](https://access.redhat.com/errata/RHSA-2018:2309) (access.redhat.com) vendor-advisory - [104232](http://www.securityfocus.com/bid/104232) (securityfocus.com) vdb-entry - [RHSA-2018:1653](https://access.redhat.com/errata/RHSA-2018:1653) (access.redhat.com) vendor-advisory - [RHSA-2018:2171](https://access.redhat.com/errata/RHSA-2018:2171) (access.redhat.com) vendor-advisory - [RHSA-2018:1635](https://access.redhat.com/errata/RHSA-2018:1635) (access.redhat.com) vendor-advisory - [\[debian-lts-announce\] 20180916 \[SECURITY\] \[DLA 1506-1\] intel-microcode security update](https://lists.debian.org/debian-lts-announce/2018/09/msg00017.html) (lists.debian.org) mailing-list - [RHSA-2018:2394](https://access.redhat.com/errata/RHSA-2018:2394) (access.redhat.com) vendor-advisory - [RHSA-2018:1710](https://access.redhat.com/errata/RHSA-2018:1710) (access.redhat.com) vendor-advisory - [RHSA-2018:1659](https://access.redhat.com/errata/RHSA-2018:1659) (access.redhat.com) vendor-advisory - [RHSA-2018:1711](https://access.redhat.com/errata/RHSA-2018:1711) (access.redhat.com) vendor-advisory - [DSA-4273](https://www.debian.org/security/2018/dsa-4273) (debian.org) vendor-advisory - [RHSA-2018:1738](https://access.redhat.com/errata/RHSA-2018:1738) (access.redhat.com) vendor-advisory - [RHSA-2018:1674](https://access.redhat.com/errata/RHSA-2018:1674) (access.redhat.com) vendor-advisory - [RHSA-2018:3396](https://access.redhat.com/errata/RHSA-2018:3396) (access.redhat.com) vendor-advisory - [RHSA-2018:1667](https://access.redhat.com/errata/RHSA-2018:1667) (access.redhat.com) vendor-advisory - [USN-3654-2](https://usn.ubuntu.com/3654-2/) (usn.ubuntu.com) vendor-advisory - [RHSA-2018:1662](https://access.redhat.com/errata/RHSA-2018:1662) (access.redhat.com) vendor-advisory - [RHSA-2018:1630](https://access.redhat.com/errata/RHSA-2018:1630) (access.redhat.com) vendor-advisory - [RHSA-2018:1647](https://access.redhat.com/errata/RHSA-2018:1647) (access.redhat.com) vendor-advisory - [RHSA-2018:1967](https://access.redhat.com/errata/RHSA-2018:1967) (access.redhat.com) vendor-advisory - [USN-3655-2](https://usn.ubuntu.com/3655-2/) (usn.ubuntu.com) vendor-advisory - [RHSA-2018:3399](https://access.redhat.com/errata/RHSA-2018:3399) (access.redhat.com) vendor-advisory - [RHSA-2018:2060](https://access.redhat.com/errata/RHSA-2018:2060) (access.redhat.com) vendor-advisory - [RHSA-2018:1690](https://access.redhat.com/errata/RHSA-2018:1690) (access.redhat.com) vendor-advisory - [USN-3653-1](https://usn.ubuntu.com/3653-1/) (usn.ubuntu.com) vendor-advisory and 47 more in the [record on cve.org](https://www.cve.org/CVERecord?id=CVE-2018-3639) ## Timeline 1. ID reserved Dec 28, 2017 2. Record published May 22, 2018 3. Record last updated May 29, 2026 ## Look up another CVE ## About CubePath CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection. [Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection) Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:02 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)