VulnerabilityPublished 30 Oct 2026

CVE-2026-118775: Forge · ASN.1 OID first arc truncation in asn1.oidToDer

Affects node-forgeSource GCVE Database

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Authoritative record:CVE-2026-118775· Low 3.7

Not known to be exploited · CVSS 3.7 Low : upgrade to 1.4.1 when convenient.

Data as of 31 Oct 2026, 01:55 UTC

CVSS 3.1 base score

3.7Low

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	3.7

Patch: Available – fixed in 1.4.1

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Oct 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 30 Oct 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 node-forge to 1.4.1.

Affected software

Product	Affected	Fixed in
npmnode-forge	Affected <1.4.1	Fixed in 1.4.1

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

AI-suggested

Upgrade node-forge to version 1.4.1 or later, where the vulnerability is fixed. In this version, asn1.oidToDer() throws an error for OIDs with out-of-range first arcs and correctly encodes and decodes the first subidentifier. If upgrading immediately is not possible, validate OID strings from untrusted input before passing them to node-forge, ensuring the first arc is 0, 1, or 2, and the second arc is at most 39 when the first arc is 0 or 1.

Description

The node-forge library's function asn1.oidToDer() improperly encoded Object Identifier (OID) strings with out-of-range first arcs, causing them to be encoded as different, trusted OIDs. This flaw was an incomplete fix of a previous vulnerability and affected versions prior to 1.4.1. The issue was fixed in version 1.4.1 by rejecting out-of-range first arcs and correctly encoding the first subidentifier. The vulnerability allows an attacker to cause applications that accept untrusted OID strings and encode them with node-forge to emit a different OID than intended, potentially bypassing string-based OID checks. There is no impact on confidentiality or availability, and DER parsing is unaffected.

Impact

The vulnerability allows an attacker to supply OID strings with out-of-range first arcs that are encoded by node-forge as different, trusted OIDs. This can cause applications that validate or authorize OIDs as strings before encoding to emit a different OID than intended, potentially bypassing string-based validation or authorization controls. There is no impact on confidentiality or availability, and DER parsing is unaffected. The impact is limited to integrity, specifically the integrity of OID encoding in applications using node-forge versions prior to 1.4.1.

Summary

The vulnerability in node-forge's asn1.oidToDer() function arises from a lack of range checking on the first two arcs of an OID string. According to X.690 section 8.19, the first two arcs are encoded as one subidentifier (40 * arc1 + arc2), where arc1 must be 0, 1, or 2, and arc2 must be at most 39 if arc1 is 0 or 1. The function did not enforce these constraints, allowing out-of-range values to wrap and encode as different OIDs, such as encoding '0.42.840.113549.1.1.1' as the DER for '1.2.840.113549.1.1.1' (rsaEncryption). Additionally, valid OIDs with first subidentifiers above 127 were incorrectly encoded and decoded because the first subidentifier was treated as a single byte. The fix in node-forge 1.4.1 enforces range checks on the first arcs and encodes/decodes the first subidentifier in base 128. This vulnerability affects applications that accept untrusted OID strings and encode them with node-forge, potentially causing them to emit a different OID than the one checked or authorized. Parsing of DER-encoded OIDs is not affected. The issue is tracked as CVE-2026-118775 and was fixed in node-forge version 1.4.1.

CWE-190Integer Overflow or Wraparound (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
Requirements
Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.3 (opens in a new tab)
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 31 Oct 2026, 01:55 UTC

WeaknessesCWE-190

Technical details

References

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