CVE-2026-18024: PostgreSQL ascii() function reads past end of buffer

mediumCVSS 4.3CVE-2026-18024

CSIRTS triage

vendor: PostgreSQL product: PostgreSQL Memory corruption Information disclosure

What: The ascii() function reads past the end of its buffer during string processing.
Who is affected: PostgreSQL deployments using the ascii() function with untrusted input.
Urgency: Medium severity (CVSS 4.3); potential for information disclosure or denial of service.
Action: Update PostgreSQL and review ascii() function usage with untrusted data.

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

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 4.3
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-18024

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-2026-180240.30% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-18024	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] PostgreSQL: Multiple vulnerabilitiescert-bund
unknownUSN-8653-1: PostgreSQL vulnerabilitiesubuntu
unknownMultiple vulnerabilities in PostgreSQL (August 14, 2026)cert-fr-avis
mediumCVE-2026-18024: Buffer over-read in PostgreSQL ascii() SQL function allows a user to disclose up to 3 bytes af…nvd

Recent advisories for PostgreSQL ascii

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.

mediumCVE-2026-18024: Buffer over-read in PostgreSQL ascii() SQL function allows a user to disclose up to 3 bytes af…nvd · 2026-08-13