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Fencer Vulns
high 8.7

CVE-2025-47934 json

OpenPGP.js's message signature verification can be spoofed

published 2025-05-19 17 mo ago modified 2026-09-10 1 mo ago also EUVD-2025-15798 , GHSA-8qff-qr5q-5pr8

cvss
8.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

OpenPGP.js is a JavaScript implementation of the OpenPGP protocol. Startinf in version 5.0.1 and prior to versions 5.11.3 and 6.1.1, a maliciously modified message can be passed to either `openpgp.verify` or `openpgp.decrypt`, causing these functions to return a valid signature verification result while returning data that was not actually signed. This flaw allows signature verifications of inline (non-detached) signed messages (using `openpgp.verify`) and signed-and-encrypted messages (using `openpgp.decrypt` with `verificationKeys`) to be spoofed, since both functions return extracted data that may not match the data that was originally signed. Detached signature verifications are not affected, as no signed data is returned in that case. In order to spoof a message, the attacker needs a single valid message signature (inline or detached) as well as the plaintext data that was legitimately signed, and can then construct an inline-signed message or signed-and-encrypted message with any data of the attacker's choice, which will appear as legitimately signed by affected versions of OpenPGP.js. In other words, any inline-signed message can be modified to return any other data (while still indicating that the signature was valid), and the same is true for signed+encrypted messages if the attacker can obtain a valid signature and encrypt a new message (of the attacker's choice) together with that signature. The issue has been patched in versions 5.11.3 and 6.1.1. Some workarounds are available. When verifying inline-signed messages, extract the message and signature(s) from the message returned by `openpgp.readMessage`, and verify the(/each) signature as a detached signature by passing the signature and a new message containing only the data (created using `openpgp.createMessage`) to `openpgp.verify`. When decrypting and verifying signed+encrypted messages, decrypt and verify the message in two steps, by first calling `openpgp.decrypt` without `verificationKeys`, and then passing the returned signature(s) and a new message containing the decrypted data (created using `openpgp.createMessage`) to `openpgp.verify`.

Patch / fix

  • npm openpgp 5.11.3, 6.1.1
  • openpgpjs openpgpjs 5.11.3, 6.1.1

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
npm openpgp
>=5.0.1, <5.11.3
>=6.0.0-alpha.0, <6.1.1
5.11.3
6.1.1

Affected products

  • openpgpjs openpgpjs

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.