What is CVE-2018-25285?

CVE-2018-25285 is a medium-severity vulnerability in Fathom, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.5/10. Published 2026-04-26.

How severe is CVE-2018-25285?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Fathom

CVE-2018-25285

Fathom 2.4 contains a buffer overflow vulnerability in the Authorization Code field that allows local attackers to crash the application by submitting an oversized input string. Attackers can paste a 6000-byte payload into the Authorization Code field and click Activate to trigger a denial of service condition.

Vulnerability class: Buffer Overflow

Published 2026-04-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.001 (2.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 2.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

Fathom — versions 2.4

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

www.exploit-db.com/exploits/45294 (exploit)
fathom.concord.org/ (product)
fathom.concord.org/download/ (product)
www.vulncheck.com/advisories/fathom-denial-of-service-via-authorization-code-bu… (third-party-advisory)

Frequently asked questions

What is CVE-2018-25285?: CVE-2018-25285 is a medium-severity vulnerability in Fathom, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.5/10. Published 2026-04-26.
How severe is CVE-2018-25285?: Medium severity. CVSS v3 base score is 5.5 out of 10.