What is CVE-2019-8338?

CVE-2019-8338 is a medium-severity vulnerability in Gpg-Pgp Project, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.9/10. Published 2019-05-16.

How severe is CVE-2019-8338?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Is CVE-2019-8338 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Gpg-Pgp Project

CVE-2019-8338

The signature verification routine in the Airmail GPG-PGP Plugin, versions 1.0 (9) and earlier, does not verify the status of the signature at all, which allows remote attackers to spoof arbitrary email signatures by crafting a signed email with an invalid signature. Also, it does not verify the validity of the signing key, which allows remote attackers to spoof arbitrary email signatures by crafting a key with a fake user ID (email address) and injecting it into the user's keyring.

Published 2019-05-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.017 (76.7th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 76.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000

Affected products

Gpg-Pgp Project

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

github.com/Airmail/AirmailPlugIn-Framework/commits/master (Patch, Third Party Advisory)
seclists.org/fulldisclosure/2019/Apr/38 (mailing-list, Mailing List, Third Party Advisory)
packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html (VDB Entry, Third Party Advisory)
www.openwall.com/lists/oss-security/2019/04/30/4 (mailing-list, Mailing List, Third Party Advisory)
github.com/RUB-NDS/Johnny-You-Are-Fired (Third Party Advisory)
github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdf (Third Party Advisory)

Frequently asked questions

What is CVE-2019-8338?: CVE-2019-8338 is a medium-severity vulnerability in Gpg-Pgp Project, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.9/10. Published 2019-05-16.
How severe is CVE-2019-8338?: Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2019-8338 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.