Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\ProgramData using .NET BinaryFormatter without implementing input validation or deserialization safeguards. Because the file can be created or modified by a local user in default configurations, an attacker can supply a crafted serialized payload that is deserialized by the privileged process, resulting in arbitrary code execution as SYSTEM.
CVE-2026-27749
HIGHPre-NVD 7.87.8—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-03-05. a secondary CVSS source baseline 7.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.8
- EG Score
- 7.8(medium)
- EG Risk
- 40(Track)EG Risk 40/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity78% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 25%
- KEV
- Not listed
Published
March 5, 2026
Last Modified
June 17, 2026
References (3)
- security@nortonlifelockhttps://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions
- security@nortonlifelockhttps://www.avira.com/en/internet-security
- security@nortonlifelockhttps://www.gendigital.com/us/en/contact-us/security-advisories/
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-28 15:36 UTCEPSS rescore
- 2026-07-27 13:51 UTCEG score recompute
- 2026-07-27 13:51 UTCGHSA enrichment
Related CVEs(same CWE)
Same CWE
10 shownCWE-502
- CVE-2017-10992EG 9.8EPSS p95CRITICAL
- CVE-2013-4521EG 9.8EPSS p90CRITICAL
- CVE-2014-1860EG 9.8CRITICAL
- CVE-2016-1000027EG 9.8EPSS p98CRITICAL
- CVE-2014-3699EG 9.8CRITICAL
- CVE-2017-10934EG 9.8CRITICAL
- CVE-2016-9498EG 9.8EPSS p97CRITICAL
- CVE-2016-9483EG 9.8CRITICAL
- CVE-2015-2020EG 9.8CRITICAL
- CVE-2017-15692EG 9.8EPSS p91CRITICAL
Frequently asked(5)
What is CVE-2026-27749?
CVE-2026-27749 is a high vulnerability published on March 5, 2026. Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\ProgramData using .NET BinaryFormatter without…
When was CVE-2026-27749 disclosed?
CVE-2026-27749 was first published in the National Vulnerability Database on March 5, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27749 actively exploited?
CVE-2026-27749 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 75.3% of all scored CVEs.
What is the CVSS score of CVE-2026-27749?
CVE-2026-27749 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-27749?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27749, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-27749
Is Your Infrastructure Affected by CVE-2026-27749?
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