What is CVE-2015-0843?

CVE-2015-0843 is a critical-severity vulnerability in Yubiserver, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2025-06-26.

How severe is CVE-2015-0843?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2015-0843 known to be exploited?

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

Buffer overflow in Yubiserver

CVE-2015-0843

yubiserver before 0.6 is prone to buffer overflows due to misuse of sprintf.

Vulnerability class: Buffer Overflow

Published 2025-06-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.001

Affected products

Yubiserver — versions 0
Debian Yubiserver — versions 0.2-2, 0.5-2

Weakness classification (CWE)

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

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

bugs.debian.org/796495 (Mailing List, Issue Tracking, Vendor Advisory)
www.include.gr/debian/yubiserver/ (Release Notes)

Frequently asked questions

What is CVE-2015-0843?: CVE-2015-0843 is a critical-severity vulnerability in Yubiserver, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2025-06-26.
How severe is CVE-2015-0843?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2015-0843 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.