CVE-2020-12656

Memory exhaustion via unreleased GSS domain references

Published May 5, 2020 · Updated Aug 4, 2024

Memory leak in Linux kernel 5.6.10 and earlier allows local users to exhaust memory through rpcsec_gss_krb5 module unloads. gss_mech_free in net/sunrpc/auth_gss/gss_mech_switch.c omits required domain_release calls during module unload, retaining domain references and consuming kernel memory. Exploitation requires privileges to load and unload kernel modules; the dispute notes those privileges already permit deliberate memory exhaustion.

CVSS severity5.5
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in Linux kernel 5.6.10 and earlier allows local users to exhaust memory through rpcsec_gss_krb5 module unloads. gss_mech_free in net/sunrpc/auth_gss/gss_mech_switch.c omits required domain_release calls during module unload, retaining domain references and consuming kernel memory. Exploitation requires privileges to load and unload kernel modules; the dispute notes those privileges already permit deliberate memory exhaustion.

The record

CVE
CVE-2020-12656
Published
May 5, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-401, T1499.001
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 5, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.001OS Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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