CVE Feed
3.7 Low

Forge: ASN.1 OID first arc truncation in asn1.oidToDer

CVE-2026-118775

Summary asn1.oidToDer() did not range-check the first two arcs of an OID string, so an OID such as 0.42.840.113549.1.1.1 or 4294977127.18.840.113549.1.1.1 was encoded as the DER of a different OID (here rsaEncryption, 1.2.840.113549.1.1.1). This is an incomplete fix of CVE-2025-66030. Fixed in node-forge 1.4.1. Details X.690 section 8.19 encodes the first two arcs of an OID as one subidentifier, 40 arc1 + arc2, where the first arc is 0, 1 or 2 and the second arc is at most 39 when the first is 0 or 1. asn1.oidToDer() in lib/asn1.js computed that value with no range check and wrote it with putByte(), which keeps only the low 16 bits. Out-of-range first arcs therefore produced the encoding of a different OID: 0.42.840.113549.1.1.1 gives 40 0 + 42 = 42 and 4294977127.18.840.113549.1.1.1 wraps to 42, both the first byte of rsaEncryption. The fix for CVE-2025-66030 (GHSA-65ch-62r8-g69g, node-forge 1.3.2) added a 32-bit check for the later arcs only. A related encoding bug made valid OIDs with a first subidentifier above 127 (2.48 and higher, e.g. 2.999) encode and decode incorrectly, because the first subidentifier was always written and read as a single byte. The fix rejects…

Assessment

CVSS
3.7 (v3.1)
Severity
Low
EPSS
0.00313% chance of exploitation in the next 30 days
Known exploited
Not listed in CISA KEV
Exploit availability
Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published
30 October 2026
Last updated
30 October 2026
Affected
npm · node-forge
Weakness
CWE-190

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

At the source

References

Query this programmatically

Agents can read this through the MCP endpoint, or over HTTP:

curl https://cve.zerocrew.in/api/cve/CVE-2026-118775