Cyber Resilience

CVE-2026-11789

Memory Safety in Redhat Enterprise Linux 10.0 … 9.0

Published
09 June 2026
Modified
30 June 2026
Patch / advisory
CVSS Score v3.1 4.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0028 20th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-11789 is a medium-severity Wrap or Wraparound (CWE-191) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 4.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-2 (Flaw Remediation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A flaw was found in 389 Directory Server. The SMD5 password storage plugin performs unsigned integer underflow when computing salt length from a crafted password hash shorter than 16 bytes, causing a buffer over-read that crashes the LDAP server during…

more

authentication.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Integer underflow in auth plugin enables crafted input to crash LDAP server (application exploitation for DoS).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-11791Same product: Redhat 389 Directory Server
CVE-2026-9064Same product: Redhat 389 Directory Server
CVE-2026-11788Same product: Redhat 389 Directory Server
CVE-2026-11611Same product: Redhat 389 Directory Server
CVE-2024-6237Same product: Redhat 389 Directory Server
CVE-2026-15041Same product: Redhat 389 Directory Server
CVE-2026-11787Same product: Redhat 389 Directory Server
CVE-2026-14940Same product: Redhat 389 Directory Server
CVE-2026-11786Same product: Redhat 389 Directory Server
CVE-2026-12528Same product: Redhat 389 Directory Server

Affected Assets

redhat
directory server
11.0, 12.0, 13.0
redhat
389 directory server
all versions
redhat
enterprise linux
10.0, 7.0, 8.0, 9.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SI-2 Flaw Remediation
  • SI-16 Memory Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces validation of password hash inputs to reject lengths < 16 bytes before SMD5 salt-length calculation occurs.

prevent

Requires timely patching of the unsigned-integer-underflow flaw in the SMD5 plugin to eliminate the buffer over-read.

prevent

Memory-protection mechanisms can contain or abort the buffer over-read before it produces a server-wide crash.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 full match
prevents

Secure SDLC practices directly prevent integer underflow defects via input validation, bounds checking, and static analysis.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis can surface underflow flaws after they are introduced.

PR.PS-02 partial match
prevents

Routine patching can remediate known underflow bugs once they are discovered in deployed software.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development catches integer underflow defects before release.

prevents

Secure development lifecycle mandates input validation and arithmetic checks that prevent integer underflow.

prevents

Application security requirements include bounds checking and safe arithmetic to avoid underflow conditions.

prevents

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards directly prescribe safe integer handling and overflow/underflow prevention.

References