What is CVE-2026-103436?

CVE-2026-103436 is a low-severity vulnerability in Apcupsd, classified under CWE-457. CVSS score: 3.7/10. Published 2026-09-30.

How severe is CVE-2026-103436?

Low severity. CVSS v3 base score is 3.7 out of 10.

Vulnerability in Apcupsd

CVE-2026-103436

apcupsd through 3.14.14 discloses uninitialized stack memory in getupsvar() in src/cgi/upsfetch.c (used by upsstats.cgi, multimon.cgi, and upsfstats.cgi. On the single-field path, when the matched STATUS line has fewer than three whitespace-separated tokens, sscanf("%*s %*s %s", answer) performs no assignment but the function returns success, and thus the caller prints the uninitialized destination buffer into the HTTP response.

Published 2026-09-30 · last modified 2026-09-30.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Apcupsd

Weakness classification (CWE)

CWE-457

References

Frequently asked questions

What is CVE-2026-103436?: CVE-2026-103436 is a low-severity vulnerability in Apcupsd, classified under CWE-457. CVSS score: 3.7/10. Published 2026-09-30.
How severe is CVE-2026-103436?: Low severity. CVSS v3 base score is 3.7 out of 10.