3.7

CVE-2026-103436: apcupsd Use of Uninitialized Variable

CVSS: 3.7v3.1LowDeferred
AliasesUBUNTU-CVE-2026-103436DEBIAN-CVE-2026-103436
Published 30-09-2026Last modified 02-10-2026
Open JSON

Vulnerability summary

CVE-2026-103436 is a low (CVSS 3.7) Use of Uninitialized Variable vulnerability in apcupsd. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 20.5% of scored vulnerabilities.

Overall risk
15/100
0100
Low · default modelHow is this calculated?
CVSS score
3.7/10
010
Low · v3.1 (CVE.org)
EPSS score
0.29%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 30-09-2026
    PublishedVulnerability first disclosed.
  2. 02-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.29%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

01-10-202619-10-2026
EPSS score
0.29%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Apcupsd1 product
Debian1 product
  • apcupsdAll versions (No fix recorded)
Ubuntu1 product
  • apcupsdAll versions (No fix recorded)

3 vendors · 3 products

References

6 links