Low severity · published Sep 30, 2026
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
3.7
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AP
apcupsd · apcupsd
through 3.14.14 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103436
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103436
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2493140
github.com
https://github.com/therealbstern/apcupsd/blob/224d19d5faa508d04267f6135fe53d50800550de/src/cgi/upsfetch.c#L240
sourceforge.net
https://sourceforge.net/projects/apcupsd/
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