CVE-2026-103436

Severity: low (CVSS 3.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-30 · updated 2026-10-02
Weakness: CWE-457

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.

Affected products

apcupsd: through 3.14.14

References

https://bugzilla.redhat.com/show_bug.cgi?id=2493140
https://github.com/therealbstern/apcupsd/blob/224d19d5faa508d04267f6135fe53d50800550de/src/cgi/upsfetch.c#L240
https://sourceforge.net/projects/apcupsd/

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