VulnerabilityPublished 13 Nov 2026

CVE-2026-128081: AutoMapper · Denial of Service via uncontrolled recursion that bypasses MaxDepth

Affects AutoMapperSource GCVE Database

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Mentioned vulnerabilities

CVE-2026-32933

Authoritative record:CVE-2026-128081· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 16.3.0 soon.

Data as of 13 Nov 2026, 19:37 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	7.5

Patch: Available – fixed in 16.3.0, 15.1.4

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade AutoMapper to 16.3.0; AutoMapper to 15.1.4.

Affected software

Product	Affected	Fixed in
NuGetAutoMapper	Affected >=16.0.0 <16.3.0	Fixed in 16.3.0
NuGetAutoMapper	Affected <15.1.4	Fixed in 15.1.4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available in AutoMapper versions 16.3.0 and 15.1.4 that addresses this issue. Users should upgrade to these or later versions. As a workaround, explicitly set MaxDepth on derived maps and maps involving object or interface-typed members. For dictionary or dynamic sources and recursive type converters, limit input nesting depth before mapping, as no configuration workaround exists for these paths.

Description

AutoMapper versions prior to 16.3.0 and before 15.1.4 contain a denial of service vulnerability due to uncontrolled recursion that bypasses the MaxDepth limit. This flaw affects polymorphic maps, runtime-typed members, dictionary and dynamic sources, and recursive type converters, allowing deeply nested attacker-controlled data to cause a StackOverflowException and crash the application. The issue is fixed in versions 16.3.0 and 15.1.4.

Impact

An attacker can cause a denial of service by supplying deeply nested data that triggers unbounded recursion in AutoMapper, leading to a StackOverflowException and application crash. This impacts availability but does not affect confidentiality or integrity. The crash occurs after a few thousand nesting levels on typical Windows stack sizes.

Summary

The vulnerability in AutoMapper arises because the MaxDepth recursion limit, introduced in a prior fix (CVE-2026-32933), does not apply to several mapping paths including derived type maps, runtime-typed members (object or interface types), nested Dictionary<string, object> or ExpandoObject sources, and recursive type converters using ConvertUsing. These paths allow unbounded recursion when mapping deeply nested data, resulting in a StackOverflowException that terminates the process. The fix ensures derived maps inherit MaxDepth, runtime map calls check for sufficient stack space and throw a catchable InsufficientExecutionStackException instead of overflowing. Workarounds include explicitly setting MaxDepth on derived and runtime-typed maps and limiting input depth for dictionary/dynamic sources and recursive converters.

CWE-674Uncontrolled Recursion (opens in a new tab)
Class weakness
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
Implementation
Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.
Implementation
Increase the stack size.
Attack patterns
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Nov 2026, 19:37 UTC

WeaknessesCWE-674

Technical details

References

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