VulnerabilityPublished 17 Sep 2026Updated 19 Oct 2026

CVE-2026-93053: Linux kernel · speakup: keyhelp: guard letter_offsets possible out-of-range indexing

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in fd339b9ef0accb2c24a5285df842552ebf5eb146 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in fd339b9ef0accb2c24a5285df842552ebf5eb146, d7deb90c4cd086cb111f0ecc9da021218fbde1b0, ca4489b3e54666a7cac7294e71a3cf64e5e95286 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ c6e3fd22cd538365bfeb82997d5b89562e077d42, < fd339b9ef0accb2c24a5285df842552ebf5eb146	Fixed in fd339b9ef0accb2c24a5285df842552ebf5eb146
LinuxLinux	Affected ≥ c6e3fd22cd538365bfeb82997d5b89562e077d42, < d7deb90c4cd086cb111f0ecc9da021218fbde1b0	Fixed in d7deb90c4cd086cb111f0ecc9da021218fbde1b0
LinuxLinux	Affected ≥ c6e3fd22cd538365bfeb82997d5b89562e077d42, < ca4489b3e54666a7cac7294e71a3cf64e5e95286	Fixed in ca4489b3e54666a7cac7294e71a3cf64e5e95286
LinuxLinux	Affected ≥ c6e3fd22cd538365bfeb82997d5b89562e077d42, < 5310334762c3f08f51dc2414344dd47492c07d1d	Fixed in 5310334762c3f08f51dc2414344dd47492c07d1d
LinuxLinux	Affected ≥ c6e3fd22cd538365bfeb82997d5b89562e077d42, < 900cd6e5ef46bd15153762fb26bb03f874fccc52	Fixed in 900cd6e5ef46bd15153762fb26bb03f874fccc52
LinuxLinux	Affected ≥ c6e3fd22cd538365bfeb82997d5b89562e077d42, < 6b39969c724d39b6062efa354dc2d38442bfd021	Fixed in 6b39969c724d39b6062efa354dc2d38442bfd021

Description

In the Linux kernel, the following vulnerability has been resolved: speakup: keyhelp: guard letter_offsets possible out-of-range indexing help_init() builds letter_offsets[] by using the first byte of each function name as an index via `(start & 31) - 1`. If function_names are overridden from sysfs (root) with a name starting outside [a–z], the index underflows or exceeds the array, leading to OOB write. Function names can be overridden with the following commands as root: modprobe speakup_soft echo "0 _bad" > /sys/accessibility/speakup/i18n/function_names # then press Insert+2 on /dev/tty This fix checks the first letter in help_init(), and if it is not in the [a–z] range the function returns an error to the caller. Eventually this error is propagated to drivers/accessibility/speakup/main.c:2217, which causes a bleep sound.

References

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