The Shrimpers went in front after Barry Corr headed home a right-wing corner from Kevan Hurst. But Phil Brown's side were forced to settle for a frustrating share of the spoils when Paris Cowan-Hall's long-range shot struck the crossbar before hitting the back of goalkeeper Daniel Bentley and rolling in to the net.
Wycombe came closest to scoring in the first half when Anthony Stewart's header from Max Kretzschmar's right-wing corner was superbly saved by Bentley.
Corr then had an effort ruled out for offside before he nodded in his eighth goal of the season, converting Kevan Hurst's corner from the right in the 63rd minute of the match.
Seven minutes later, though, Wycombe had a fortuitous equaliser and the visitors nearly won it twice late on with substitute Dean Morgan having an effort tipped wide by Bentley before the same player struck the top of the crossbar right at the death.