speakup: keyhelp: guard letter_offsets possible out-of-range indexing

These records connect through source-stated identifiers. Shared identifiers or dates alone do not establish shared exposure, root cause or applicability.

CVE-2026-93053 · Microsoft / collected KEV context

cve-program · CVE-2026-93053

• https://git.kernel.org/stable/c/fd339b9ef0accb2c24a5285df842552ebf5eb146
• https://git.kernel.org/stable/c/900cd6e5ef46bd15153762fb26bb03f874fccc52
• https://git.kernel.org/stable/c/6b39969c724d39b6062efa354dc2d38442bfd021
• https://git.kernel.org/stable/c/2e91ab73f9beb659f581e2a6a09f79ace1140905
• https://git.kernel.org/stable/c/d7deb90c4cd086cb111f0ecc9da021218fbde1b0
• https://git.kernel.org/stable/c/5310334762c3f08f51dc2414344dd47492c07d1d
• https://git.kernel.org/stable/c/ca4489b3e54666a7cac7294e71a3cf64e5e95286
• https://git.kernel.org/stable/c/6a19ad4d68c95185308cd9e5d169b10a2cf236c8

No related operational record is retained in the current change model.