Answer in brief
CVE-2026-18663 records a Medium severity (CVSS 5.9) vulnerability in 389-ds-base: 389-ds-base: pre-authentication double-free in get_ldapmessage_controls_ext() via critical session tracking control. The current sources do not mark it as known exploited. Affected software not mapped in the current feed; confirm the named product and version against your inventory.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
Affected software not mapped in the current feed; confirm the named product and version against your inventory.
Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 12, 2026
A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function frees the parsed controls array on the Session Tracking critical-control rejection path without clearing the SLAPI_REQCONTROLS pblock slot. Operation teardown then frees the same pointer again, causing a double-free. An unauthenticated remote attacker can trigger this with a single BIND request carrying a critical Session Tracking control, resulting in heap corruption and potential denial of service.
Quoted source text, attributed separately from HOL analysis.