DSA-6403-1 nss - security update

unknownCVE-2026-16389

Tomoya Nakanishi discovered a flaw in nss, the Mozilla Network Security Service library, which may result in execution of arbitrary code if a specially crafted certificate is processed. https://security-tracker.debian.org/tracker/DSA-6403-1

CSIRTS triage

vendor: Mozilla product: nss Code injection

What: A flaw in nss may allow execution of arbitrary code if a specially crafted certificate is processed.
Who is affected: Users of the nss library are affected.
Urgency: Remediation is urgent due to the potential for arbitrary code execution.
Action: Update nss to the latest version to mitigate the vulnerability.

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

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Details

Source: Debian Security Advisories (INTL · vendor-psirt · site)
Severity: unknown
Published: 2026-07-29
Exploitation: Not in CISA KEV at last sync

Original advisory: https://lists.debian.org/debian-security-announce/2026/msg00314.html

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-2026-163890.42% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 35% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-16389	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

high[NEW] [high] Mozilla Firefox and Firefox ESR: Multiple vulnerabilitiescert-bund
unknownMultiple vulnerabilities in Mozilla Thunderbird (July 23, 2026)cert-fr-avis
unknownMozilla Products Multiple Vulnerabilitieshkcert
unknownMultiple vulnerabilities in Mozilla products (July 22, 2026)cert-fr-avis
criticalCVE-2026-16389: Incorrect boundary conditions, integer overflow in the Libraries component in NSS. This vulner…nvd