Unknown severity · Source severity not reportedCVE-2026-102731

Apache Directory LDAP API: Denial of service via excessive memory allocation in BER decode

Answer in brief

CVE-2026-102731 records a Unknown severity vulnerability in Apache Directory LDAP API: Denial of service via excessive memory allocation in BER decode. The current sources do not mark it as known exploited. The current feed maps Apache Software Foundation/org.apache.directory.api:api-asn1-ber (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 2, 2026Updated Oct 2, 2026Source checked Oct 2, 2026First seen by HOL Oct 2, 2026Material review Oct 2, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. 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 scope and exposure questions

The current feed maps Apache Software Foundation/org.apache.directory.api:api-asn1-ber (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Apache Software Foundation/org.apache.directory.api:api-asn1-bergeneric	>=1.2.0 <1.2.9	1.2.9

Recommended response

Check inventory. Check lockfiles and deployed manifests for Apache Software Foundation/org.apache.directory.api:api-asn1-ber.
Review the reported fix. Update Apache Software Foundation/org.apache.directory.api:api-asn1-ber to 1.2.9 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 2, 2026

Sources and claim methodology

Source referencelists.apache.org

Upstream source description

Memory allocation with excessive size value vulnerability in Apache Directory LDAP API. A malicious peer (or a MITM) can send a small BER-encoded response causing a large memory allocation before any data is received. This can lead to an OutOfMemoryError and denial of service. The client JVM OOMs (OutOfMemoryError bypasses the DecoderException handlers) or pins the large allocation per connection while the attacker stalls. A handful of connections exhausts any heap. The same bytes from an unauthenticated pre-bind client hit any embedding server that did not set MAX_PDU_SIZE_ATTR. This issue affects Apache Directory LDAP API: from 1.2.0 before 1.2.9. Users are recommended to upgrade to version 1.2.9, which fixes the issue.

Quoted source text, attributed separately from HOL analysis.