[UPDATE] [hoch] Golang Go: Mehrere Schwachstellen

CSIRTS triage

What

Multiple vulnerabilities in Golang Go allow remote denial of service, cross-site scripting, security bypass, and data manipulation.

Who is affected

Go applications and systems running vulnerable Go versions are exposed to remote anonymous attackers.

Urgency

High; remote attackers can cause denial of service and bypass security controls without authentication.

Action

Upgrade Golang Go to the latest patched release addressing CVE-2026-33818, CVE-2026-39821, and related CVEs.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source

CERT-Bund (BSI) Security Advisories (DE · national-cert · site)

Severity

high

Published

2026-09-11

Exploitation

Not in CISA KEV at last sync

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2850

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

• Low exploitation riskCVE-2026-338180.57% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 45% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-398210.69% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 51% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-466000.55% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 44% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-568530.57% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 45% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-568580.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 24% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-568590.57% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 45% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-568600.52% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-568620.57% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 45% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-568640.30% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 22% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-568650.11% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all EPSS-scored CVEs.

Referenced CVEs

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

• medium[UPDATE] [mittel] Golang Go-Module (Net, Image, Crypto: Mehrere Schwachstellencert-bund
• unknownMultiples vulnérabilités dans les produits VMware (07 septembre 2026)cert-fr-avis
• highCVE-2026-56865: A malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a r…nvd
• highCVE-2026-56864: A malicious GOSUMDB was capable of serving arbitrary module content not contained within the t…nvd
• highCVE-2026-56862: Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of…nvd
• mediumCVE-2026-56860: Previously, resolving relative paths containing parent directory ('..') segments performed str…nvd
• highCVE-2026-56859: Previously, DecodeElement would reset the depth counter causing it to never fire; this could l…nvd
• mediumCVE-2026-56858: Previously, pathological inputs could close an unescaped '/' early, allowing for attack-contro…nvd
• highCVE-2026-56853: When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new …nvd
• highCVE-2026-33818: Enforce a recursion limit in Unmarshal to prevent stack exhaustion when parsing deeply-nested,…nvd
• high[NEW] [high] Oracle Solaris third-party components: Multiple vulnerabilitiescert-bund
• highCVE-2026-56853: Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check in net/httpmsrc

Recent advisories for Golang Go

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

• medium[UPDATE] [mittel] Golang Go-Module (Net, Image, Crypto: Mehrere Schwachstellencert-bund · 2026-09-11
• medium[UPDATE] [mittel] Golang Go: Mehrere Schwachstellencert-bund · 2026-09-11
• high[UPDATE] [hoch] Golang Go: Mehrere Schwachstellencert-bund · 2026-09-11
• high[UPDATE] [hoch] Golang Go: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriffcert-bund · 2026-09-11
• high[UPDATE] [hoch] Golang Go: Mehrere Schwachstellencert-bund · 2026-09-11
• medium[UPDATE] [mittel] Golang Go: Mehrere Schwachstellencert-bund · 2026-09-11

More from CERT-Bund (BSI) Security Advisories

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• medium[UPDATE] [mittel] Linux Kernel: Schwachstelle ermöglicht Denial of Service2026-09-11
• medium[UPDATE] [mittel] Linux Kernel: Mehrere Schwachstellen2026-09-11
• high[UPDATE] [hoch] OpenSSL: Mehrere Schwachstellen2026-09-11