diff --git a/base/poco/Foundation/src/inflate.c b/base/poco/Foundation/src/inflate.c index ac333e8c2ed..cd018573dee 100644 --- a/base/poco/Foundation/src/inflate.c +++ b/base/poco/Foundation/src/inflate.c @@ -759,8 +759,9 @@ int flush; if (copy > have) copy = have; if (copy) { if (state->head != Z_NULL && - state->head->extra != Z_NULL) { - len = state->head->extra_len - state->length; + state->head->extra != Z_NULL && + (len = state->head->extra_len - state->length) < + state->head->extra_max) { zmemcpy(state->head->extra + len, next, len + copy > state->head->extra_max ? state->head->extra_max - len : copy);